Carbon cloth as a 3D matrix for growth of enzyme mediating films of 1,10-Phenanthroline-5,6-dione

Encapsulation of the heterocyclic quinoid species, 1,10-phenanthroline-5,6-dione (PDon) was achieved via an enzymatically assisted electrodeposition approach on carbon transducers. The reagentless glucose biosensing methodology took advantage of a layered biopolymer with biocompatible conducting bioink formulation. The PDon mediating layer served as a proton and electron acceptor for FADH 2 glucose oxidase cofactor regeneration. Scanning electron microscopy revealed interesting microstructures on both glassy carbon (GC) and woven fabric carbon cloth (CC) substrates while electrochemical film studies established surface confined behaviour and the expected proton coupled electron transfer process. Quantitative glucose investigations involved differential pulse voltammetry (DPV) and constant potential approaches in phosphate buffer (pH 6.0 and 7.4). DPV studies resulted in sensitivity 1.00 × 10 -7 ± 4.27 × 10 -9 A mmol -1 L (2.0-4.0 mmol L -1 ) and 1.20 × 10 -5 ± 8.64 × 10 -7 A mmol -1 L (1.0-4.95 mmol L -1 ) for GC and CC electrodes respectively, with the latter resulting in limit of detection of 0.55 ± 0.30 mmol L -1 and apparent Michaelis Menton constant, K m ′ = 0.79 ± 0.01 mmol L -1 . The redox behaviour of the CC transducer was found to be intact following > 10 months at 4 °C.