A nanoporous coordination polymer (NPCP) was prepared from palladium(II) chloride and 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole and is shown to act as a peroxidase mimetic. It can catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by H2O2 which is formed on enzymatic oxidation of glucose by glucose oxidase. Based on these findings, a sensitive glucose test was worked out at 652 nm where the intensity if the greenish-blue product is related to the actual concentration of glucose. Figures of merit include (a) rather low Km value (30 μM) which evidences the strong binding affinity of the NPCP toward glucose, (b) a high v(max) (8.5 M·s−1), (c) a 47 nM detection limit, (d) a lifetime of a month, (e) a wide working pH range (2–10), and (f) a 25–80 °C temperature range. The assay was applied to non-invasive determination of glucose assay in tear, saliva where the detection limits are found to be 61 and 91 nM, respectively.
AHMT–Pd NPCP Glucose TMB Peroxidase Colorimetry Portable test kit
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Ms. Vinita and Dr. Narsingh R. Nirala are greatly acknowledged to the CSIR, JRF (File no- 09/013(0641)/2016-EMR-I) and SERB N-PDF (PDF/2016/000243) respectively for fellowship. Authors are also thankful to CIF, IIT (BHU) Varanasi for providing instrumentation facility. Vinita, NR Nirala and M Tiwari are responsible for all the experiments and data. All the authoths have contributed in manuscript writing.
Compliance with ethical standards
The author(s) declare that they have no competing interests.
Nirala NR, Khandelwal G, Kumar B, Vinita, Prakash R , Kumar V (2017) One step electro-oxidative preparation of graphene quantum dots from wood charcoal as a peroxidase mimetic. Talanta 173:36–43. doi: https://doi.org/10.1016/J.TALANTA.2017.05.061, 2017
Li Z, Sheng L, Meng A, Xie C, Zhao K (2016) A glassy carbon electrode modified with a composite consisting of reduced graphene oxide, zinc oxide and silver nanoparticles in a chitosan matrix for studying the direct electron transfer of glucose oxidase and for enzymatic sensing of glucose. Microchim Acta 183:1625–1632. https://doi.org/10.1007/s00604-016-1791-xCrossRefGoogle Scholar
Ortiz-Gómez I, Salinas-Castillo A, García AG, Álvarez-Bermejo JA, de Orbe-Payá I, Rodríguez-Diéguez A, Capitán-Vallvey LF (2018) Microfluidic paper-based device for colorimetric determination of glucose based on a metal-organic framework acting as peroxidase mimetic. Microchim Acta 185:47. https://doi.org/10.1007/s00604-017-2575-7CrossRefGoogle Scholar
Kaya İ, Erçağ A, Avcı A, Çulhaoğlu S (2014) Synthesis, characterization and conductivity properties of novel oligomer Schiff bases derived from 4-Amino-3-hydrazino-5-mercapto-1, 2, 4-triazole and their reactions with VO(IV), cu(II) ions. J Inorg Organomet Polym Mater 24:665–675. https://doi.org/10.1007/s10904-014-0036-xCrossRefGoogle Scholar