One-step construction of a molybdenum disulfide/multi-walled carbon nanotubes/polypyrrole nanocomposite biosensor for the <i>ex-vivo</i> detection of dopamine in mouse brain tissue

Vijayaraj, Kathiresan,Dinakaran, Thirumalai,Lee, Yujeong,Kim, Suhkmann,Kim, Hyung Sik,Lee, Jaewon,Chang, Seung-Cheol Elsevier 2017 Biochemical and biophysical research communication Vol. No.

<P><B>Abstract</B></P> <P>We developed a new strategy for construction of a biosensor for the neurotransmitter dopamine. The biosensor was constructed by one-step electrochemical deposition of a nanocomposite in aqueous solution at pH 7.0, consisting of molybdenum disulfide, multi-walled carbon nanotubes, and polypyrrole. A series of analytical methods was performed to investigate the surface characteristics and the improved electrocatalytic effect of the nanocomposite, including cyclic voltammetry, electrochemical impedance spectroscopy, field-emission scanning electron microscopy, atomic force microscopy, and Raman spectroscopy. The constructed biosensor showed high sensitivity (1.130 μAμM<SUP>−1</SUP>cm<SUP>−2</SUP>) with a dynamic linearity range of 25–1000 nM and a detection limit of 10 nM. Additionally, the designed sensor exhibited strong anti-interference ability and satisfactory reproducibility. The practical application of the sensor was manifested for the <I>ex vivo</I> determination of dopamine neurotransmitters using brain tissue samples of a mouse Parkinson's disease model.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ex vivo dopamine detection in mouse brain tissues of Parkinson's disease model. </LI> <LI> Nanocomposite constructed by one-step electrochemical approach. </LI> <LI> The synergetic performance enhancement of the sensor by nanocomposite. </LI> </UL> </P>

Spectral, Electrochemical, Fluorescence, Kinetic and Anti-microbial Studies of Acyclic Schiff-base Gadolinium(III) Complexes

Vijayaraj, A.,Prabu, R.,Suresh, R.,Kumari, R. Sangeetha,Kaviyarasan, V.,Narayanan, V. Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

A new series of acyclic mononuclear gadolinium(III) complexes have been prepared by Schiff-base condensation derived from 5-methylsalicylaldehyde, diethylenetriamine, tris(2-aminoethyl) amine, triethylenetetramine, N,N-bis(3-aminopropyl)ethylene diamine, N,N-bis(aminopropyl) piperazine, and gadolinium nitrate. All the complexes were characterized by elemental and spectral analyses. Electronic spectra of the complexes show azomethine (CH=N) within the range of 410-420 nm. The fluorescence efficiency of Gd(III) ion in the cavity was completely quenched by the higher chain length ligands. Electrochemical studies of the complexes show irreversible one electron reduction process around -2.15 to -1.60 V The reduction potential of gadolinium(III) complexes shifts towards anodic directions respectively upon increasing the chain length. The catalytic activity of the gadolinium(III) complexes on the hydrolysis of 4-nitrophenylphosphate was determined. All gadolinium(III) complexes were screened for antibacterial activity.

Performance Oriented Docket-NoC (Dt-NoC) Scheme for Fast Communication in NoC

Vijayaraj, M.,Balamurugan, K. The Institute of Electronics and Information Engin 2016 Journal of semiconductor technology and science Vol.16 No.3

Today's multi-core technology rapidly increases with more and more Intellectual Property cores on a single chip. Network-on-Chip (NoC) is an emerging communication network design for SoC. For efficient on-chip communication, routing algorithms plays an important role. This paper proposes a novel multicast routing technique entitled as Docket NoC (Dt-NoC), which eliminates the need of routing tables for faster communication. This technique reduces the latency and computing power of NoC. This work uses a CURVE restriction based algorithm to restrict few CURVES during the communication between source and destination and it prevents the network from deadlock and livelock. Performance evaluation is done by utilizing cycle accurate RTL simulator and by Cadence TSMC 18 nm technology. Experimental results show that the Dt-NoC architecture consumes power approximately 33.75% 27.65% and 24.85% less than Baseline XY, EnA, OEnA architectures respectively. Dt-NoC performs good as compared to other routing algorithms such as baseline XY, EnA, OEnA distributed architecture in terms of latency, power and throughput.

Development of Disposable Immunosensors for Rapid Determination of Sildenafil and Vardenafil in Functional Foods

Vijayaraj, Kathiresan,Lee, Jun Hyuck,Kim, Hyung Sik,Chang, Seung-Cheol The Korean Society of Food Hygiene and Safety 2017 한국식품위생안전성학회지 Vol.32 No.2

본 연구의 목적은 screen printed 탄소계 전극에 기반하여 기능성 식품중에 포함된 소량의 Sildenafil과 Vardenafil(SDF 및 VDF)을 쉽게 검출하기 위한 전류계 면역센서를 개발하고자 하였다. 본 연구에서 개발한 면역센서는 horseradish peroxidase로 labeling 시킨 후 비경쟁적 샌드위치 ELISA 측정법에 의한 원리를 이용하였다. 개발된 센서는 그래핀 산화물 및 키토산(ErGO-CS) 복합체를 단순한 전기화학적 증착에 의해 screen printed 탄소계 전극을 이용하는 원리이며, 감지된 화학물질을 평가하고 센서특성을 최적화하기 위해 전기 화학적 임피던스분광법, 순환 전압 전류법 등을 포함한 일련의 전기화학적 실험방법에 기초하여 완성되었다. 본 연구에서 개발된 센서는 100 pg/mL ~ 300 ng/mL 농도의 SDF 및 VDF에 대하여 직선상의 농도-의존적인 반응을 나타내었다. 또한 최저 검출 한계는 55 pg/mL이었으며, 센서의 민감도는 $1.02{\mu}Ang/mL/cm^2$로 산출되었다. 센서의 성능은 7.1%의 상대 표준편차로 매우 우수한 재현성을 나타내었다. 본 연구에서 개발된 센서의 전략적 가치는 향후 건강기능식품중에 함유된 SDF 및 VDF과 같은 의약품의 미량을 현장에서 쉽게 분석 할 수 있어서 비용-효과적 측면에서 그 가치가 우수하다는 것을 제시한다. We introduced disposable amperometric immunosensors for the detection of Sildenafil and Vardenafil (SDF/VDF) based on screen printed carbon electrodes. The developed immunosensors were used as a non-competitive sandwich-type enzyme immunoassay with a horseradish peroxidase label. The sensors were constructed on screen printed carbon electrodes by the simple electrochemical deposition of a reduced graphene oxide and chitosan (ErGO-CS) composite. To evaluate the sensing chemistry and optimize the sensor characteristics, a series of electrochemical experiments were carried out including electrochemical impedance spectroscopy, cyclic voltammetry and amperometry. The sensors showed a linear response to SDF/VDF concentrations in a range from 100 pg/mL to 300 ng/mL. The lower detection limit was calculated to be 55 pg/mL, the sensitivity was calculated to be $1.02{\mu}Ang/mL/cm^2$, and the sensor performance exhibited good reproducibility with a relative standard deviation (RSD) of 7.1%. The proposed sensing chemistry strategy and the sensor format can be used as a simple, cost-effective, and feasible method for the in-field analysis of SDF/VDF in functional or health supplement food samples.

Fabrication of a novel disposable glucose biosensor using an electrochemically reduced graphene oxide-glucose oxidase biocomposite

Vijayaraj, K.,Hong, S.,Jin, S. H.,Chang, S. C.,Park, D. S. Royal Society of Chemistry 2016 Analytical methods Vol.8 No.38

<P>A disposable glucose biosensor has been fabricated on the surface of a cost-effective pencil graphite electrode (PGE) by an electrochemical method, using glucose oxidase (GOx) and reduced graphene oxide (rGO). Electrochemical pre-treatment of the PGE enables the adsorption of the rGO-GOx biocomposite. The biocomposites of GOx and rGO were simply prepared by the electrochemical potential cycling method. Efficient immobilization of rGO-GOx is confirmed by field emission scanning electron microscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and cyclic voltammetry measurements. The rGO nanosheets enhance direct electron transfer (DET) between GOx and the electrode surface. Determination of glucose indirectly by O-2 reduction was achieved, which showed high sensitivity, selectivity, reproducibility and stability without a redox mediator. The sensor exhibits a linear current response for a wide range of glucose concentrations between 1.0 x 10(-5) and 1.0 x 10(-3) M (R = 0.998), and a dynamic range up to 10.0 x 10(-3) M with a detection limit of 5.8 mu M. The rGO-GOx biosensor showed an excellent anti-interference ability against electroactive species and proved to be useful for the determination of glucose in human serum samples.</P>

The drain fluid amylase level on the first postoperative day predicts pancreatic fistula in chronic pancreatitis patients undergoing Frey procedure

Vijayaraj Pavankumar,Raja Kalayarasan,Senthil Gnanasekaran,Biju Pottakkat 한국간담췌외과학회 2019 Annals of hepato-biliary-pancreatic surgery Vol.23 No.4

Backgrounds/Aims: Abdominal drains are routinely placed following Frey procedure for chronic pancreatitis (CP) despite the low incidence of pancreatic fistula (PF). The utility of the first postoperative day (POD1) drain fluid amylase (DFA) value in predicting PF in CP patients undergoing Frey procedure has not been previously reported. Methods: A prospective study of patients with CP who underwent Frey procedure between August 2014 and April 2018. A standard technique of head coring with single layer continuous pancreatojejunostomy was done in all the patients. Amylase level of the drain placed close to the pancreatojejunostomy was recorded on POD1 and 3. Postoperative PF was defined and graded as per the updated International Study Group of Pancreatic Fistula (ISGPF) guidelines. Results: Fiftyfive patients with CP who fulfilled the inclusion criteria were included in the study. All had normal preoperative serum amylase level. Three patients developed a biochemical leak and four patients developed postoperative PF (Grade B - 3 and Grade C - 1). Receiver operating characteristics (ROC) curve identified a POD1 DFA cut-off value of 326 U/L that predicted a postoperative PF with sensitivity, specificity and negative predictive value of 100%, 70%, and 100% respectively. Conclusions: The POD1 DFA is a reliable predictor of postoperative PF in CP patients who have undergone Frey procedure. The PF can be confidently excluded in patients who have a POD1 DFA less than 326 U/L.

Spectral, Electrochemical, Fluorescence, Kinetic and Anti-microbial Studies of Acyclic Schiff-base Gadolinium(III) Complexes

A. Vijayaraj,R. Prabu,R. Suresh, L. Jagadish,R. Sangeetha Kumari,V. Kaviyarasan,V. Narayanan 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

A new series of acyclic mononuclear gadolinium(III) complexes have been prepared by Schiff-base condensation derived from 5-methylsalicylaldehyde, diethylenetriamine, tris(2-aminoethyl) amine, triethylenetetramine, N,N-bis(3-aminopropyl)ethylene diamine, N,N-bis(aminopropyl) piperazine, and gadolinium nitrate. All the complexes were characterized by elemental and spectral analyses. Electronic spectra of the complexes show azomethine (CH=N) within the range of 410-420 nm. The fluorescence efficiency of Gd(III) ion in the cavity was completely quenched by the higher chain length ligands. Electrochemical studies of the complexes show irreversible one electron reduction process around −2.15 to −1.60 V The reduction potential of gadolinium(III) complexes shifts towards anodic directions respectively upon increasing the chain length. The catalytic activity of the gadolinium(III) complexes on the hydrolysis of 4-nitrophenylphosphate was determined. All gadolinium(III) complexes were screened for antibacterial activity.

Development of Disposable Immunosensors for Rapid Determination of Sildenafil and Vardenafil in Functional Foods

Kathiresan Vijayaraj,이준혁,김형식,장승철 한국식품위생안전성학회 2017 한국식품위생안전성학회지 Vol.32 No.2

We introduced disposable amperometric immunosensors for the detection of Sildenafil and Vardenafil (SDF/VDF) based on screen printed carbon electrodes. The developed immunosensors were used as a non-competitive sandwich-type enzyme immunoassay with a horseradish peroxidase label. The sensors were constructed on screen printed carbon electrodes by the simple electrochemical deposition of a reduced graphene oxide and chitosan (ErGO-CS) composite. To evaluate the sensing chemistry and optimize the sensor characteristics, a series of electrochemical experiments were carried out including electrochemical impedance spectroscopy, cyclic voltammetry and amperometry. The sensors showed a linear response to SDF/VDF concentrations in a range from 100 pg/mL to 300 ng/mL. The lower detection limit was calculated to be 55 pg/mL, the sensitivity was calculated to be 1.02 μAng/ mL/cm2, and the sensor performance exhibited good reproducibility with a relative standard deviation (RSD) of 7.1%. The proposed sensing chemistry strategy and the sensor format can be used as a simple, cost-effective, and feasible method for the in-field analysis of SDF/VDF in functional or health supplement food samples.

Performance Oriented Docket-NoC (Dt-NoC) Scheme for Fast Communication in NoC

M. Vijayaraj,K. Balamurugan 대한전자공학회 2016 Journal of semiconductor technology and science Vol.16 No.3

Today’s multi-core technology rapidly increases with more and more Intellectual Property cores on a single chip. Network-on-Chip (NoC) is an emerging communication network design for SoC. For efficient on-chip communication, routing algorithms plays an important role. This paper proposes a novel multicast routing technique entitled as Docket NoC (Dt-NoC), which eliminates the need of routing tables for faster communication. This technique reduces the latency and computing power of NoC. This work uses a CURVE restriction based algorithm to restrict few CURVES during the communication between source and destination and it prevents the network from deadlock and livelock. Performance evaluation is done by utilizing cycle accurate RTL simulator and by Cadence TSMC 18 nm technology. Experimental results show that the Dt-NoC architecture consumes power approximately 33.75% 27.65% and 24.85% less than Baseline XY, EnA, OEnA architectures respectively. Dt-NoC performs good as compared to other routing algorithms such as baseline XY, EnA, OEnA distributed architecture in terms of latency, power and throughput.

New Unsymmetric Dinuclear Copper(II) Complexes of Trans-disubstituted Cyclam Derivatives: Spectral, Electrochemical, Magnetic, Catalytic, Antimicrobial, DNA Binding and Cleavage Studies

Prabu, R.,Vijayaraj, A.,Suresh, R.,Jagadish, L.,Kaviyarasan, V.,Narayanan, V. Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.5

Six new binuclear copper(II) complexes have been prepared by template condensation of the dialdehydes 1,8-[bis(3-formyl-2-hydroxy-5-methyl)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-a) and 1,8-[bis(3-formyl-2-hydroxy-5-bromo)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-b) with appropriate aliphatic diamines, and copper(II) perchlorate. The structural features of the complexes have been confirmed by elemental analysis, IR, UV-vis and mass spectra etc. The electrochemical behavior of all the copper(II) complexes show two irreversible one electron reduction process. The room temperature magnetic moment studies depict the presence of an antiferromagnetic interaction in the binuclear complexes. The catechol oxidation and hydrolysis of 4-nitrophenylphosphate were carried out by using the complexes as catalyst. The antimicrobial screening data show good results. The binding of the complexes to calf thymus DNA (CT DNA) has been investigated with absorption and emission spectroscopy. The complex [$Cu_2L^{1a}$] displays significant cleavage property of circular plasmid pBR322 DNA in to linear form. Spectral, electrochemical, magnetic and catalytic studies support the distortion of the copper ion geometry that arises as the macrocyclic ring size increases.