비색법을 이용한 모자간 우식 활성의 상관성

장소영 연세대학교 대학원 2015 국내석사

According to ecological plaque theory, the process of tooth caries is directly related to the total amount of organic acid produced by bacteria in an oral cavity. The colorimetric test is one of several caries activity tests. It takes cultures of oral plaque and visually demonstrates the total amount of organic acid produced by that plaque. The purpose of this study is not only to assess a new colorimetric caries activity test, Cariview, but also to assess the correlation of caries activity between mothers and their children, comparing the Cariview test with the specific bacteria culture test, CRT bacteria. Mothers and their children under 6 years participated in this study with informed consent. Mothers filled out a questionnaire first. Then each subject had an oral examination and the above two caries activity tests were administered. All data was statistically analyzed using the Pearson correlation test, Spearman correlation test, Fisher’s exact test and Mann-Whitney U test at the 0.05 significance level. The results were as followed. 1. Cariview scores showed statistically significant correlation with children’s caries experience(r=0.598, P<0.01) and showed higher correlation than CRT bacteria scores. 2. Cariview scores showed statistically significant correlation with the number of decayed teeth in both mothers and children(P<0.05). 3. Both caries activity tests showed the correlation of caries experience or caries activity between mothers and their children is not statistically significant. Cariview colorimetric test properly reflects children’s caries experience and current caries status and it is also easy to use with uncooperative children. Therefore, it is supposed that Cariview colorimetric test would be clinically useful for predicting future caries risk and establishing a preventative strategy at a pediatric dental clinic. Meanwhile, it is suggested that the lack of correlation of caries experience or caries activity between mothers and their children in this study reflects the high availability of nursery spaces in Korea today, and that further studies will be needed on this subject. 생태적 치태 가설에 따르면 치아 우식 발생 과정은 구강 내 전체 미생물이 생산한 최종 유기산의 양과 직접적인 관련이 있다. 비색법은 치태를 배양하여 생성된 최종 유기산의 양을 pH 지시약을 첨가하여 시각적으로 밝히는 우식 활성 검사 방법이다. 지금까지 비색법을 이용한 우식 활성 연구 사례는 적으며 특히 모자간 우식 활성의 상관성 연구는 거의 없었다. 본 연구의 목적은 새로운 비색법인 Cariview를 이용한 우식 활성 검사의 타당성 및 모자간 우식 활성의 상관성 평가를 기존의 특정 세균 배양법인 CRT bacteria 검사와 비교하여 평가하는 것이다. 만 6세 미만 어린이-어머니 34쌍(총 68명)이 사전 동의 하에 연구에 참여하였다. 설문 조사 및 구강 검사 후 우식 활성 검사인 Cariview와 CRT bacteria 검사를 각각의 대상자에게 시행하였다. 자료는 Pearson correlation test, Spearman correlation test, Fisher’s exact test 및 Mann-Whitney U test로 통계 분석하였고 유의수준은 0.05로 정하였다. 실험 결과 Cariview 점수는 어린이의 우식경험유치수(dft)와 통계적으로 유의한 상관성을 나타냈고(r=0.598, p<0.01) 상관 정도는 CRT bacteria 점수보다 높았다. Cariview 점수는 어머니와 어린이의 우식치아수(DT, dt)와 통계적으로 유의한 상관성을 나타냈다(p<0.05). Cariview와 CRT bacteria 검사 모두에서 모자간 우식 경험 및 우식 활성은 통계적으로 유의한 상관성을 나타내지 않았다(p>0.05). Cariview 비색법은 어린이의 치아 우식 경험 및 현재의 치아 우식 상태를 적절히 반영하며 검사 시행 또한 용이하다. 따라서 소아치과에서 우식 위험도를 예측하고 예방 전략을 수립하는 데 임상적으로 유용할 것으로 판단된다. 한편 모자간 우식 경험 및 우식 활성의 낮은 상관성 결과는 최근 한국 사회의 높은 영·유아 보육 기관 이용률 추세가 반영된 결과로 추정되며 이러한 현 실태를 반영한 추가적인 연구 진행이 필요할 것으로 여겨진다.

소아에서 Cariview®를 이용한 우식 활성 비색 검사와 치아우식 경험

조성현 연세대학교 대학원 2014 국내석사

생태학적 치태 가설에 따르면, 치아우식증 발생에는 특정 세균의 수보다 치태 전체 세균의 산 생산 능력이 중요한 요소이다. 그래서 현재 널리 쓰이고 있는Dentocult SM?와 같은 특정 세균 수를 측정하는 우식 활성 검사는 치아우식 예측에 한계점을 가진다. 반면 새로운 우식 활성 비색 검사인 Cariview?는 새로운 pH 지시약을 사용해서 치태 세균의 산 생산 능력을 더 잘 반영할 수 있다. 본 연구의 목적은 어린이에서 Cariview?와 치아우식 경험(dmft index)과의 상관성을 평가하고, Cariview?를 Dentocult SM?과 비교하는 것이다. 135명의 어린이(만5세 이하, 남자 61명, 여자 74명)가 사전동의 하에 연구에 참여했다. 본 연구는 어린이의 구강관리 습관태도에 대한 설문조사를 한 후, 구강검사를 통해 치아우식과 치태 지수를 기록했으며, Cariview?와 Dentocult SM? 두 가지 우식 활성 검사를 제조사 지시에 따라 시행하였다. 통계분석은 분산분석 및 사후검정, T검정, 스피어만 상관분석, ROC 곡선분석을 시행하였다(α=0.05). 상관 분석 결과, Cariview?는 어린이 치아우식 경험과 중등도의 상관관계를 보였고(r=0.43, p<0.01), Dentocult SM?과 중등도의 상관관계를 보였다(r=0.38, p<0.01). 치아우식 진단에 있어 Cariview?는 민감도 68.8%, 특이도 69.2%, ROC 곡선 분석의 곡선하면적(AUC)이 0.686으로 Dentocult SM?에 비해 양호한 수치를 보였다. 치아우식이 없는 군과 치아우식이 있는 군을 비교한 결과, Cariview? 점수에서 통계적으로 유의한 차이가 있었다(p<0.01). 그러나 이번 연구에서 어린이의 구강관리 습관태도는 치아우식 경험이나 우식 활성 검사 결과와 유의한 상관성을 보이지 않았다. 치아우식 진단의 정확성과 설명력은 Cariview?가 Dentocult SM?보다 약간 더 양호한 것으로 여겨진다. 더욱이 Cariview?는 비협조적인 어린이에게도 시행이 쉽고 편리하며 시각적인 색상으로 교육적 효과도 있다. 따라서, 치아우식에 민감한 어린이를 밝혀내고 예방 전략을 수립하는 데에 Cariview?가 임상적으로 유용하게 사용될 수 있을 것으로 사료된다.

Multiplex Colorimetric Diagnosis for Point of Care Test Using Encoded Microparticle

정윤진 서울대학교 대학원 2019 국내박사

In this dissertation, a multiplex colorimetric diagnosis platform using encoded microparticles is proposed. Multiple target biomolecules can be detected by an office scanner as a concept of point of care tests within low-resource settings. The encoded microparticles guarantee high multiplexing capacity up to millions. Detection using gold nanoparticles in platform was demonstrated with assay results according to the color change of the encoded microparticles. Realizing scanner-based multiplex assay, this platform’s novelty lies in fabrication of the encoded particles with two materials and introduction of a signal enhancement step to the multiplex bead-based assay using deposition of gold for higher sensitivity. The encoded microparticles, in which the engraved codes indicate the types of target molecules, are prepared to capture target. The design of the particles including the size and the materials were determined, to analyze the assay results with images taken by scanners. Also, the high-throughput fabrication methods have been developed to guarantee that more than 1000 particles can be fabricated in less than 3 minutes. The encoded particles with a single code are coated by silica and chemically conjugated to one type of capture molecules. This pairing guarantees the code to indicate the type of target molecules in multiplexing assay. The encoded microparticles targeting various molecules are pooled and reacted to samples with target molecules. After capturing targets on the multiple types of encoded particles, the particles conjugated with targets react with detection molecules. The detection molecules include gold nanoparticles to change the levels of target molecules into color signals. If the signal is too weak, a signal enhancement step is introduced using gold deposition to the seed gold nanoparticles with targets. After the whole colorimetric assay, the reacted particles are imaged using an office scanner, from which the code and the assay results are analyzed using image processing. The size of the microparticles was considered according to the proper resolution of the scanners. To be applied to various situations, two types of particles have been developed and utilized. 900μm particles with 2.5 million kinds of character codes and 300μm particles with 70-256 kinds of binary codes are developed to be scanned with 1200 and 4800 dpi respectively. As a proof of concept to show a wide range of applications, proteins and genes are detected. Using 4-plex assay, multiple sclerosis autoimmune disease patients are classified from healthy people with p<0.0001 in an unpaired t-test. Using 3-plex assay, bacterial meningitis genes are detected within 1000 molecules. This scanner-based assay platform can expand the clinical impacts of the multiplex assay. This platform can be applied to various circumstances where high-resource settings have not been set. With operators and scanners, the platform can be applied to multiplex assay in high multiplexing capacity and high throughput. 본 학위 논문에서는 동시다발적으로 단백질이나 유전물질을 색변화를 통해 진단할 수 있는 플랫폼을 개발하였다. 본 플랫폼은 최종적으로 오피스 스캐너로 분석할 수 있기에 고가의 장비 없이 환자와 보다 가까운 곳에서 활용될 수 있는 기술이다. 코드화된 미세입자를 통해 한 샘플에서 동시에 여러 가지 진단을 가능하게 하였으며, 금 나노입자를 통해 분석 결과가 색 변화로 나타나 스캐너로 검출할 수 있도록 하였다. 해당 기술을 구현하기 위하여 미세입자를 두 가지 물질로 구성되도록 제작하였고 빠르게 대용량으로 제작하는 기술 역시 개발하였다. 또한 색변화로 적은 양의 물질을 검출할 수 있도록 신호 증폭 기술을 입자 기반 진단 기술에 적용하였다. 본 플랫폼을 개발하기 위해서 우선 표적 생체물질을 잡을 수 있는 코드화된 미세입자를 제작하였다. 스캐너로도 분석에 충분한 이미지를 얻을 수 있도록 크기와 물질 등의 디자인이 고려되었다. 본 미세입자를 3분 이내에 1 000 개 이상 제작할 수 있는 방법 역시 개발하였다. 제작된 코드화된 미세입자는 표적 생체물질만을 붙잡을 수 있도록 실리카 코팅된 후 화학적으로 포획분자가 코드 별로 다르게 부착된다. 여러 물질을 표적하는 코드화된 미세입자들은 함께 섞인 뒤에 표적물질이 있는 샘플과 동시다발적으로 반응한다. 표적물질을 반응 시킨 후에는 표적물질의 존재를 색변화로 나타낼 수 있도록 미세입자에 부착된 표적물질에만 골드 나노파티클이 붙게 된다. 신호가 약한 경우 골드 나노파티클의 크기를 키우는 반응을 통해 신호를 증폭시켜 확인한다. 반응이 모두 끝난 이후 미세입자들은 스캐너로 관측이 되고, 이미지 처리를 통해 코드와 표적물질의 양에 따라 변화된 색변화를 분석한다. 코드는 표적 물질의 종류를 나타내고, 색변화는 표적물질의 존재 정도에 비례하여 나타난다. 미세입자의 크기는 스캐너의 해상도에 직접적으로 연관이 있으므로 1 200 dpi 에서 분석이 가능한 900μm 미세입자와 4 800 dpi 에서 분석이 가능한 300μm 미세입자를 개발하였다. 각 입자는 문자코드를 활용하여 250만 개 이상의 코드를 가질 수 있고, 2진법의 코드를 활용하여 70 에서 256 개의 코드를 가질 수 있도록 개발되었다. 본 플랫폼이 다양한 진단 상황에 적용될 수 있음을 보이기 위하여, 환자 샘플에서 자가면역질환 관련 항체를 검출하는 실험과 적은 양의 박테리아 뇌수막염 관련 유전체를 검출하는 실험을 진행하였다. 4 종류의 동시다발적 분석을 통해 자가면역 질환 환자와 건강한 사람을 비쌍체 t 검정에서 p<0.0001 로 구분할 수 있었으며, 3 종류의 동시다발적 분석을 통해 박테리아 뇌수막염 관련 유전체를 1 000 개까지 검출해낼 수 있었다. 본 플랫폼을 통해 동시다발적 진단 기술의 의료 혜택을 보다 널리 확장시킬 수 있을 것으로 기대된다. 본 플랫폼은 고가의 장비들이 구축되지 않은 환경에서도 스캐너만 있다면 구현될 수 있으며 많은 수의 표적 물질을 동시에 확인할 수 있고 병렬적으로 많은 샘플을 진단할 수 있도록 개발되었기 때문이다.

Paper-Based Point-of-Care Testing Colorimetric Nanosensor Containing Dried but Highly Redispersible and Reactive Gold Nanoparticles

김수지 성균관대학교 일반대학원 2017 국내석사

We developed a simple and easy method of constructing a paper-based colorimetric nanosensor utilizing dried gold nanoparticles (AuNPs) that were capable of re-dispersion and reaction in the presence of an aqueous analyte. By coating paper with a thin polydimethylsiloxane (PDMS) layer and treating the PDMS surface with both bovine serum albumin (BSA) and sucrose, we could introduce a hydrophilic layer onto the paper substrate. The hydrophilic layer not only allowed long-term storage of dried AuNPs and minimization of the coffee ring effect, but also helped with the re-dispersal of AuNPs in aqueous samples without significant losses. Through passivation of AuNPs with polyvinylpyrrolidone (PVP), the re-dispersed AuNPs not only showed high colloidal stability but also had significantly less nonspecific interactions with the serum layer. More importantly, PVP-passivated AuNPs could aggregate in the presence of short linking ligands such as 1,4-dithiothreitol (DTT), with a resultant clear color change from red to blue. Taking advantage of chlorine-induced DTT oxidation, we developed a paper based colorimetric sensor for detection of residual chlorine in drinking water. The AuNPs in the paper device were blue in the absence of hypochlorous acid (HOCl), but turned red in its presence. The degree of color change was dependent on the amount of HOCl, and the dynamic range of the sensor could be tuned by adjusting the amount of DTT used in the detector. Based on this technique, an inexpensive but highly reliable point-of-care testing device could be fabricated that could help detect various analytes.

Colorimetric detection of DNA methylation based on 5-methylcytosine antibody-functionalized polydiacetylene(5-mC Ab-PDA) sensor

사공희연 인제대학교 일반대학원 2023 국내석사

DNA methylation is one of the epigenetic modifications caused by adding of a methyl group at the carbon-5 position of the cytosine ring. The silencing of tumor suppressor genes due to hypermethylation within the promoter region of oncogenes not only leads to abnormal cell proliferation and mutation, but also contributes to the pathogenesis of cancer. In this study, colorimetric detection of methylated DNA is proposed by functionalizing a 5-methylcytosine antibody (5-mC Ab) that can specifically bind to 5-methylcytosine (5-mC) on polydiacetylene (PDA). The 5-methylcytosine antibody-functionalized polydiacetylene (5-mC Ab-PDA) was composed of matrix diacetylene lipid (10,12-pentacosadiynoic acid; PCDA) and newly synthesized 5-methylcytosine antibody-decorated diacetylene monomer (5-mC Ab-PCDA). As a result, the 5-mC Ab-PDA showed a distinct color change from blue to purple as the concentration of methylated DNA amplified with 5-mC dNTP mix from the colon cancer cell increased. The colorimetric response (CR, %) of 5-mC Ab-PDA to the concentration of methylated DNA was quantified, the CR value (%) of 5-mC Ab-PDA under the addition of methylated DNA at a maximum concentration of 50 nM was 19.07 ± 3.19%. In addition, a good linear relationship was shown between the concentration of methylated DNA and the CR value (%) of 5-mC Ab-PDA, and the calculated limit of detection is ~8.039 nM. On the other hand, the 5-mC Ab-PDA showed no color change when amplified DNA via dNTP mix from a colon cancer cell line and unmethylated DNA from a normal colon cell line were added. These results show that 5-mC Ab-PDA can detect methylated DNA with the naked eye through optical properties without additional equipment, and thus has excellent clinical potential as a point-of-care testing sensor in the field of early cancer diagnosis. DNA 메틸화는 사이토신 고리의 탄소 5번 위치에 메틸 그룹을 추가함으로써 발생하는 후성 유전적 변형 중 하나이다. 특히, 종양유전자의 프로모터 영역 내 과메틸화로 인한 종양억제유전자의 침묵은 비정상적인 세포 증식 및 돌연변이를 유발할 뿐만 아니라, 암의 발병에 기여한다. 따라서, 본 연구에서는 5-메틸사이토신(5-methylcytosine; 5-mC)에 특이적으로 결합할 수 있는 5-메틸사이토신 항체(5-methylcytosine antibody; 5-mC Ab)를 폴리디아세틸렌(Polydiacthylene; PDA)에 기능화함으로써 메틸화된 DNA의 비색 검출을 목표로 한다. 5-메틸사이토신 항체로 기능화된 폴리디아세틸렌(5-mC Ab-PDA)은 매트릭스 디아세틸렌 지질(10,12-pentacosadiynoic acid; PCDA)과 새롭게 합성된 5-메틸사이토신 항체가 장식된 디아세틸렌 단량체(5-mC Ab-PCDA)로 구성되었다. 그 결과, 결장암 세포주로부터 얻어져 5-mC dNTP로 증폭된 메틸화된 DNA의 농도가 증가함에 따라 5-mC Ab-PDA는 청색에서 보라색으로의 뚜렷한 색상 변화를 보였다. 메틸화된 DNA의 농도에 대한 5-mC Ab-PDA의 비색 반응(Colorimetric response; CR, %)이 정량화되었으며, 최대 농도인 50 nM의 메틸화된 DNA 첨가 시 5-mC Ab-PDA의 CR 값(%)은 19.07 ± 3.19%를 나타내었다. 또한, 메틸화된 DNA의 농도와 5-mC Ab-PDA의 CR 값(%) 사이에 좋은 선형 관계를 보여주었으며, 계산된 검출 한계는 ~8.039 nM이다. 반면에, 결장암 세포주로부터 얻어져 dNTP로 증폭된 DNA 및 정상 결장 세포주의 메틸화되지 않은 DNA 첨가 하에는 5-mC Ab-PDA의 색 변화가 관찰되지 않았다. 이러한 결과는 5-mC Ab-PDA가 광학적 특성을 통해 별도의 장비 없이 육안으로 DNA 메틸화를 검출할 수 있어, 조기 암 진단 분야에서 현장 진단용 센서로서 우수한 임상 잠재력을 가질 수 있음을 보여준다.

Peptide-based biofunctional molecules : detection of cells and therapeutic application

전희철 Graduate School, Yonsei University 2012 국내박사

Paper based bio-analytical devices for the detection of biomarkers from saliva

최서연 Graduate School, Yonsei University 2017 국내박사

Saliva contains various biomarkers reflecting ones in blood and consequently has long been utilized for the laboratory, clinical diagnosis, and monitoring of patients’ healthcare. The advantages of salivary diagnostics are non-invasive and ease to sample collection, elimination of fear of needles, increased patients’ acceptance, and reduced risks of disease transmission between healthcare workers and patients. The most widely used, commercially available point-of-care testing (POCT) diagnostic assay is the lateral flow immunoassay (LFA), also known as paper-based analytical device (µ-PAD). This one-step POCT biosensor guarantees rapid diagnostic, low-cost analysis, user-friendly, simple handling, stability, and is easy to mass product. However, it has several drawbacks such as limited sample volume, semi-quantitative, expensive dispenser and relatively low sensitivity. To overcome these disadvantages, here I applied and developed this following studies: (1) A cheap and user-friendly dispenser using a fountain pen and antibody-gold conjugated nanoparticle ink to create test lines on a lateral flow immunosensor strip. (2) A simple smartphone-based measurement system consisting of a smartphone, a holder, and a lateral flow immune strip. The smartphone camera and light source were used to read the colorimetric signal from the lateral flow assay. (3) The µ-PAD was newly designed and fabricated to confine fluid flow by creating a hydrophobic channel in the paper to improve the sensitivity using the wax printer. (4) Salivary cortisol was used to evaluate stress levels related to personal characteristics with a paper-based lateral flow assay (LFA) chip and a smartphone. Variations in the level of salivary cortisol, communication apprehension, and the effects of self-efficacy via the Smartphone Linked Stress Measurement (SLSM) were studied. In conclusion, my work demonstrated that the real-time detection of salivary biomarkers by using smartphone and LFA could contribute to in vitro diagnostics in a simple, user-friendly, and inexpensive manner.

Controlled synthesis and biosensing, bioimaging and therapeutic applications of plasmonic nano-bio hybrid probes

Kumar, Sumit 서울대학교 대학원 2014 국내박사

Nanomaterials-based diagnostic and therapeutic platforms have offered significant advantages over conventional systems with regard to high sensitivity, selectivity and low cost. Among various nanomaterials, gold nanoparticles (AuNPs) possess a plethora of unique features such as size- and shape-dependent optical and electronic properties, a high surface area to volume ratio, and versatile surface-chemistry readily modifiable with ligands (including biomolecules) containing a variety of functional groups; and therefore such plasmonic nanostructures have established a centerstage amongst diverse scientific communities involving chemists, physicists, biologists and material scientists. Intelligent design and synthesis of plasmonic nanostructures and their hybrids is crucial to tune their localized surface plasmon resonance (LSPR)-based properties such as optical signaling, surface-enhanced-Raman scattering (SERS), photocatalysis and photothermal transduction, useful in biomedical applications. In spite of the proliferative growth of nanoscience in last two decades, potential real-life applications of biosensing/bioimaging/therapeutic plasmonic nanoprobes in biological systems suffer several design challenges to address the important issues such as biocompatibility (no toxicity), efficient nano-bio interfacing, sensitive signaling response and benign but effective therapeutic action. In the present thesis, we have designed and synthesized new plasmonic nanostructures/nanoassemblies which show tunable optical, SERS, enzymetic, photothermal and photocatalytic properties. We successfully demonstrated that our new nano-bio hybrid probes have potential to distinguish normal and cancer cells based on their sensitive, selective and quantitative monitoring/imaging of cellular oxidative and nitrosative stress in living cells (by optical and SERS based signaling), biodetection of glucose with clinical urinalysis trial (colorimetric/UV-Vis signaling), and organic photosensitizer-free bimodal photothermal and photodynamic therapeutic effect for cancer cells destruction. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are chemically reactive intermediates naturally produced in the living systems as the consequence of complex endogenous and exogenous biochemical reactions. Overproduction of ROS/RNS, so-called ‘the state of oxidative-stress’ is a hallmark for the pathogenesis of many diseases such as cardiovascular diseases, cancer, and neurodegenerative diseases. In chapter 1, we developed a straightforward, sensitive, and quantitative assay for the colorimetric and spectroscopic detection of various ROS and RNS such as H2O2, •OH, –OCl, NO, and O2– using glutathione-modified gold nanoparticles (GSH-AuNPs). A basic principle here is that the GSHs on the AuNP surface can be readily detached via the formation of glutathione disulfides upon the addition of ROS and RNS, and destabilized particles can aggregate to generate the plasmonic couplings between plasmonic AuNPs that trigger the red shift in UV–vis spectrum and solution color change. For nonradical species such as H2O2, this process can be more efficiently achieved by converting them into radical species via the Fenton reaction. Using this strategy, we were able to rapidly and quantitatively distinguish among cancerous and normal cells based on ROS and RNS production. Simultaneous and distinguishable quantitative monitoring of ROS and RNS in living cells is important for understanding their independent and interdependent biological roles; eventually useful in solving bio-signalling mechanistic puzzles. In chapter 2, we design a plasmonic ‘core-satellite’ nanoassembly bioprobe for SERS-based distinguishable multiplex quantitative monitoring of H2O2 and NO in living cells. We have strategically conjugated myoglobin as the dual-responsive Raman reporter in the electromagnetic ‘hot-zones’ of gold core-satellite nanoassemblies with the help of biocompatible polydopamine interface/spacer. ROS/RNS detection principle is based on the structural changes in Raman reporter heme prosthetic group of SERS bioprobe, distinctly and quantitatively monitored in living normal and cancer cells by SERS measurements upon reaction with intracellular H2O2 and NO. Metal nanostructures with highly branched morphologies are an interesting and useful new class of nanomaterials due to their plasmonically enhanced optical properties, large surface area and potential as catalytic substrates, sensing probes and building blocks for nanoscale devices. In particular, surface plasmon-derived photo-induced therapeutic effect and catalysis are highly dependent on their surface nanostructures, but the control of their branching structures is challenging. In chapter 3, we introduce a strategy for the controlled synthesis of plasmonic core-petal nanostructures (CPNs) with highly branched morphologies. The fine nanostructural engineering of CPNs was facilitated by gold chloride-induced oxidative disassembly of polydopamine corona around spherical Au nanoparticles and successive anisotropic growth of Au nanopetals. We show that CPNs can act as multifunctional nanoreactors that induce photodynamic and photothermal dual therapeutic effects and generate ROS. Near-infrared laser-activated CPNs can be used to induce the effective destruction of cancer cells via the synergistic combination of benign plasmonic hyperthermia (~42 °C) and ROS-mediated oxidative intracellular damage. It was also shown that CPNs exhibit very strong surface-enhanced Raman scattering signals, and this allows for post-mortem probing of ROS-mediated oxidative structural modifications of DNA that could be responsible for the apoptotic fate of cancer cells. Hybrid nanobiosensors working on enzyme-mimetic mechanisms are always desired to amalgamate best features of natural and synthetic systems. In chapter 4, we report a hybridized three component enzyme-mimetic glutathione-Au@Pt core-shell nanoprobe for recognition and colorimetric signaling of glucose. Unlike conventional glucose sensors based on natural enzymes, our nanoprobe is robust enough to operate in a wide pH range and even at high temperatures. In the biomimetic design, nanopockets present between Au core and porous Pt shell interfaced with glutathione ligand provide an optimal hydrophobic and hydrogen bonding environment for the efficient recognition of host sugar molecule as suggested from NMR spectroscopy and DFT calculations. GSH-Au@Pt catalyzes efficient oxidation of glucose to corresponding gluconic acids and co-produced H2O2 triggers dimerization of interfacial glutathione ligands resulting aggregation-induced plasmonic coupling between Au cores, exhibiting a visual colour change. Finally, clinical test with urine samples collected from diabetic patients were performed with very high degree of accuracy and almost no sensitivity towards common interfering urine ingredients such as ascorbic acid, proteins and cysteine.