A facile means for the improvement of sensing properties of metal-organic frameworks through control on the key synthesis variables

Kukkar, Preeti,Kukkar, Deepak,Sammi, Heena,Singh, Karanveer,Rawat, Mohit,Singh, Pritpal,Basu, Soumen,Kim, Ki-Hyun Elsevier 2018 Sensors and actuators. B Chemical Vol.271 No.-

<P><B>Abstract</B></P> <P>In this study, we investigated the optimal conditions for solvothermal-assisted synthesis of Eu-BDC-NH<SUB>2</SUB> metal organic frameworks (MOFs) to improve their sensing capacity toward some selected target metal species. To this end, we focused on the interactive relationships between key synthesis variables (e.g., the relative molar ratios (and absolute amounts) of the reactants [EuCl<SUB>3</SUB>·6H<SUB>2</SUB>O vs. amino terephthalic acid (BDC-NH<SUB>2</SUB>)], temperature, and reaction duration). It was observed that different types of MOFs synthesized under diverse conditions consistently exhibited emission profiles of Eu<SUP>3+</SUP>. However, their luminescence properties were distinguished systematically by the synthesis conditions set for each sample group. The sensing potential of luminescent MOFs was explored for detection of toxic metal ions through two approaches, i.e., direct chemosensing and indirect biomolecule mediated sensing approach. In the former, the MOFs exhibited noticeable turn-off fluorescence behavior, especially with Hg<SUP>2+</SUP> ions (i.e., a high Stern-Volmer quenching constant (K<SUB>sv</SUB>) of 6.42 × 10<SUP>5</SUP> M<SUP>−1</SUP> and limit of detection (LOD) of 0.007 M). In the latter, nanocomposites of MOFs-cyanocobalamin were characterized by a highly selective turn on fluorescence response towards Co<SUP>2+</SUP> ions (K<SUB>sv</SUB> = −6.25 × 10<SUP>3</SUP> M<SUP>−1</SUP>; LOD = 0.7 M). As such, the sensing capacity of these MOFs was distinguished efficiently by control of synthesis variables.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Optimized synthesis of Eu-BDC-NH<SUB>2</SUB>-MOFs by solvothermal approach. </LI> <LI> Effect of three variables i.e. molar ratio of reactants, temperature and time period reported has been investigated. </LI> <LI> Enhanced luminescence intensity, high reproducibility, and high stability of the MOFs upto 1 year. </LI> <LI> Significant turn off fluorescence in presence of 1 ppm Hg<SUP>2+</SUP> metal ions. </LI> <LI> Distinct turn on fluorescence of MOF-CNCbl nanocomposites in presence of 1 ppm Co<SUP>2+</SUP> ions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A comprehensive review on nano-molybdenum disulfide/DNA interfaces as emerging biosensing platforms

Kukkar, Manil,Mohanta, Girish C.,Tuteja, Satish K.,Kumar, Parveen,Bhadwal, Akhshay Singh,Samaddar, Pallabi,Kim, Ki-Hyun,Deep, Akash Elsevier 2018 Biosensors & Bioelectronics Vol.107 No.-

<P><B>Abstract</B></P> <P>The development of nucleic acid-based portable platforms for the real-time analysis of diseases has attracted considerable scientific and commercial interest. Recently, 2D layered molybdenum sulfide (2D MoS<SUB>2</SUB> from here on) nanosheets have shown great potential for the development of next-generation platforms for efficient signal transduction. Through combination with DNA as a biorecognition medium, MoS<SUB>2</SUB> nanostructures have opened new opportunities to design and construct highly sensitive, specific, and commercially viable sensing devices. The use of specific short ssDNA sequences like aptamers has been proven to bind well with the unique transduction properties of 2D MoS<SUB>2</SUB> nanosheets to realize aptasensing devices. Such sensors can be operated on the principles of fluorescence, electro-cheumuluminescence, and electrochemistry with many advantageous features (e.g., robust biointerfacing through various conjugation chemistries, facile sensor assembly, high stability with regard to temperature/pH, and high affinity to target). This review encompasses the state of the art information on various design tactics and working principles of MoS<SUB>2</SUB>/DNA sensor technology which is emerging as one of the most sought-after and valuable fields with the advent of nucleic acid inspired devices. To help achieve a new milestone in biosensing applications, great potential of this emerging technique is described further with regard to sensitivity, specificity, operational convenience, and versatility.</P> <P><B>Highlights</B></P> <P> <UL> <LI> In this review, an outlook of 2-D nanomaterial inspired biosensors is described. </LI> <LI> This article focused on MoS<SUB>2</SUB>-DNA/aptamer biosensors and their practical applications. </LI> <LI> 2-D MoS<SUB>2</SUB>-DNA interfaces are recognized as the next-generation biosensors. </LI> </UL> </P>

A New Electrolytic Synthesis Method for Few-Layered MoS₂ Nanosheets and Their Robust Biointerfacing with Reduced Antibodies

Kukkar, Manil,Tuteja, Satish K.,Sharma, Amit L.,Kumar, Vinod,Paul, Ashok K.,Kim, Ki-Hyun,Sabherwal, Priyanka,Deep, Akash American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.26

<P>We report an efficient method for the synthesis of few-layered MoS2 nanosheets and demonstrate their application in the label-free detection of the prostate-specific antigen (PSA) cancer marker. As a novel strategy, the electro-dissolution of molybdenum metal sheets in the presence of Na+ and S2- ions led to the formation of Na+ intercalated MoS2. Further exfoliation by ultrasonication yielded the desired formation of few-layered MoS2 nanosheets. After comprehensive characterization, the synthesized MoS2 nanosheets were channeled in a field-effect transistor (FET) microdevice. Chemically reduced anti-PSA antibodies were immobilized on the MoS2 channel above the FET microdevice to construct a specific PSA immunosensor. The antibodies were deliberately reduced to expose the hinge-region disulfide bonds. This approach offered a robust and site-directed immunosensing device through biointerfacing of the sulfhydryl groups (SH) in the reduced antibody with the surface S atoms of MoS2. This device was validated as an effective immunosensor with a low detection limit (10(-5)ng/mL) over a wide linear detection range (10(-5) to 75 ng/mL).</P>

A novel approach for amine derivatization of MoS₂ nanosheets and their application toward label-free immunosensor

Kukkar, Manil,Tuteja, Satish K.,Kumar, Parveen,Kim, Ki-Hyun,Bhadwal, Akhshay Singh,Deep, Akash Elsevier 2018 Analytical Biochemistry Vol.555 No.-

<P><B>Abstract</B></P> <P>The application of molybdenum disulfide (MoS<SUB>2</SUB>) nanosheets has assumed great significance in the design of next-generation biosensors. The immobilization of biomolecules on MoS<SUB>2</SUB> nanosheets has generally been achieved via hydrophobic interactions or through other complicated surface modifications. In this work, we report a novel strategy for electrochemically assisted amine derivatization of MoS<SUB>2</SUB> nanosheets. This newly proposed approach helped to immobilize the MoS<SUB>2</SUB> nanosheets with antibodies via facile EDC/NHS {N-(3-dimethylaminopropyl)-N-(ethylcarbodiimide/N-hydroxysuccinimide)} cross-linking chemistry. The MoS<SUB>2</SUB> nanosheets were first exfoliated and then electrochemically modified with 2-aminobenzylamine. Through a subsequent bioconjugation of the above amine-derivatized MoS<SUB>2</SUB> nanosheets with anti-prostate-specific antigen (PSA) antibodies, an immunosensing device was realized for the detection of the ‘prostate specific antigen’. The application of the proposed immunosensor was characterized with a low detection limit (10<SUP>−3</SUP> ng/mL) over a very wide quantitation range (10<SUP>−3</SUP> to 200 ng/mL).</P> <P><B>Highlights</B></P> <P> <UL> <LI> The bioconjugation of MoS<SUB>2</SUB> nanosheets has been processed with a novel strategy. </LI> <LI> MoS<SUB>2</SUB> nanosheets were exfoliated and electrochemically modified with 2-aminobenzylamine. </LI> <LI> MoS<SUB>2</SUB> nanosheets have been interfaced with antibodies via facile EDC/NHS cross-linking chemistry. </LI> <LI> MoS<SUB>2</SUB> nanosheets immunosensor for PSA has offered a low detection limit and a very wide range of analysis. </LI> </UL> </P>

Recent progress in biological and chemical sensing by luminescent metal-organic frameworks

Kukkar, Deepak,Vellingiri, Kowsalya,Kim, Ki-Hyun,Deep, Akash Elsevier 2018 Sensors and actuators. B Chemical Vol.273 No.-

<P><B>Abstract</B></P> <P>Luminescent metal organic frameworks (LMOFs), formed by coordinated bridging between metal ions and multidentate organic ligands with relevant fluorescent structures, have been the subject of intense research due to their tunable photoluminescent properties. The numerous permutations and combinations of available metal ions and organic linkers can yield novel LMOFs for countless applications. The luminescent characteristics of LMOFs depend upon many factors, including their structural components, coordination milieu of the metal ions, chemical structure/volume of the pore surfaces, and host-guest interactions between the LMOFs and reacting species (e.g., non-covalent interactions, coordination bonds, and π-π interactions). The combined effects of these parameters justify the expansion of their application in various fields. In addition, they are recognized as ideal candidates for biological applications due to their high loading capacity of functional molecules, facile surface modification and conjugation with biocompatible ligands (such as antibodies and proteins), tunable structural geometry, and intrinsic biocompatibility. By elaborating on these points, this article provides up-to-date information on the developments in the scientific/technological application of LMOFs, with special emphasis on the types, properties, and potential in sensing and biological applications. The discussion is further expanded to describe the major challenges and constraints of this research field.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Molybdenum disulfide quantum dot based highly sensitive impedimetric immunoassay for prostate specific antigen

Kukkar, M.,Singh, S.,Kumar, N.,Tuteja, S. K.,Kim, K. H.,Deep, A. Springer Science + Business Media 2017 Mikrochimica acta Vol.184 No.12

Application of MoS₂ modified screen-printed electrodes for highly sensitive detection of bovine serum albumin

Kukkar, M.,Sharma, A.,Kumar, P.,Kim, K.H.,Deep, A. Elsevier Pub. Co 2016 Analytica chimica acta Vol.939 No.-

The present work reports the application of a new molybdenum disulphide (MoS<SUB>2</SUB>)-based electrochemical platform for highly sensitive quantitation of an iron-binding protein, bovine serum albumin (BSA). The gold screen-printed electrodes were modified with MoS<SUB>2</SUB> nanoflakes, followed by bioconjugation with anti-BSA antibodies. Using the above bioelectrode, cyclic voltammetric analysis was carried out in the presence of a Fe<SUP>3+</SUP>/Fe<SUP>2+</SUP> redox probe which exhibited a linear response of peak current with varying concentrations of BSA up to 10 ng/mL (with a detection limit of 0.006 ng/mL). This study is novel in that it shows a considerable enhancement of signal during electrochemical sensing of a protein.

Implications and mechanism of action of gabapentin in neuropathic pain

Ankesh Kukkar,Anjana Bali,Nirmal Singh,Amteshwar Singh Jaggi 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.3

Gabapentin is an anti-epileptic agent but now itis also recommended as first line agent in neuropathic pain,particularly in diabetic neuropathy and post herpetic neuralgia. a2d-1, an auxillary subunit of voltage gated calciumchannels, has been documented as its main target and itsspecific binding to this subunit is described to producedifferent actions responsible for pain attenuation. Thebinding to a2d-1 subunits inhibits nerve injury-inducedtrafficking of a1 pore forming units of calcium channels(particularly N-type) from cytoplasm to plasma membrane(membrane trafficking) of pre-synaptic terminals of dorsalroot ganglion (DRG) neurons and dorsal horn neurons. Furthermore, the axoplasmic transport of a2d-1 subunitsfrom DRG to dorsal horns neurons in the form of anterogradetrafficking is also inhibited in response to gabapentinadministration. Gabapentin has also been shown to inducemodulate other targets including transient receptor potentialchannels, NMDA receptors, protein kinase C andinflammatory cytokines. It may also act on supra-spinalregion to stimulate noradrenaline mediated descendinginhibition, which contributes to its anti-hypersensitivityaction in neuropathic pain.

Serendipity in solution–GQDs zeolitic imidazole frameworks nanocomposites for highly sensitive detection of sulfide ions

Sammi, Heena,Kukkar, Deepak,Singh, Jaskaran,Kukkar, Preeti,Kaur, Rajwinder,Kaur, Harmanpreet,Rawat, Mohit,Singh, Gurjinder,Kim, Ki-Hyun Elsevier 2018 Sensors and actuators. B, Chemical Vol.255 No.3

<P><B>Abstract</B></P> <P>An innovative and facile sensing approach for common inorganic anions present in aqueous media has been developed using nanocomposites of europium doped graphene quantum dots (GQDs:Eu) with zeolitic imidazole frameworks (ZIF-8). GQDs:Eu, prepared initially by solvothermal approach (at <10nm in diameter), exhibited a strong and intense blue emission at 430nm when dispersed in ethanol. ZIF-8 nanocubes, synthesized on a parallel basis, were in a fairly uniform size distribution (e.g., 185nm in diameter). The formation of nanocomposites by surface adsorption (between GQDs:Eu and ZIF-8) led to significant increase in fluorescence intensity as observed through photo-luminescence spectroscopy. Their interactions with anions (e.g., in terms of variations in the fluorescence intensity) were initially checked against sulfide and other anionic species (e.g., Br<SUP>−</SUP>, Cl<SUP>−</SUP>, F<SUP>−</SUP>, and NO<SUB>3</SUB> <SUP>−</SUP>). Among the tested ions, GQDs:Eu-ZIF-8 were found to effectively and sensitively detect sulfide (S<SUP>2−</SUP>) with significantly high turn on fluorescence. The feasibility of this nanosensing system was explored further toward the detection of S<SUP>2−</SUP> ions. These nanocomposites were thus demonstrated to be feasible for solution-based sensing of S<SUP>2−</SUP> ions with high reproducibility and sensitivity at limit of detection (LOD) of 0.12ppm.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An innovative approach for detection of pollutant sulfide ions is proposed. </LI> <LI> The method is built based upon turn on fluorescence intensity of GQDs:Eu in the matrix structure of Zeolitic Imidazole Framework Nanoparticles. </LI> <LI> Among the tested ions (e.g. S<SUP>2−</SUP>, Br<SUP>−</SUP>, Cl<SUP>−</SUP>, F<SUP>−</SUP>, and NO<SUB>3</SUB> <SUP>−</SUP>), the nanocomposites sensitively detect sulfide (S<SUP>2−</SUP>) with significantly high turn on fluorescence. </LI> <LI> This nanocomposite-based sensing method exhibit high reproducibility and sensitivity at limit of detection (LOD) of 0.12ppm. </LI> <LI> This approach can be extended further to the detection of sulfide ions from environmental samples. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>An innovative and facile sensing approach for solution-based sensing of sulfide (S<SUP>2−</SUP>) anions using nanocomposites of europium doped Graphene Quantum Dots (GQDs:Eu) with Zeolitic Imidazole Frameworks (ZIF-8) has been reported. These nanocomposites are thus demonstrated as an efficient platform for solution-based sensing of S<SUP>2−</SUP> ions with high reproducibility and selectivity.</P> <P>[DISPLAY OMISSION]</P>

Exceptionally stable green-synthesized gold nanoparticles for highly sensitive and selective colorimetric detection of trace metal ions and volatile aromatic compounds

Karanveer Singh,Deepak Kukkar,Ravinder Singh,Preeti Kukkar,김기현 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.68 No.-

The manuscript reports synthesis of exceptionally stable gold nanoparticles (GNPs) using Momordica charantia fruit extract. The synthesis approach was optimized by refining three experimental variables including source of the fruit extract (peel, seed, and seed coat), pH of the solution, and temperature of the reaction medium. As synthesized GNPs showed excellent stability against various thiolated compounds (e.g., thioglycolic acid, thiourea, l-cystine, 1-dodecanethiol, and cysteamine hydrochloride). Moreover, these nanoparticles showed distinctive colorimetric responses against Cd2+ and thiophenol (TP) from their potential interferences. The limit of detection (LOD) values for Cd2+ and TP were determined as 0.186 and 0.154 μM, respectively.