Chronoampermetric detection of enzymatic glucose sensor based on doped polyindole/MWCNT composites modified onto screen-printed carbon electrode as portable sensing device for diabetes

Abstract

The enzymatic glucose sensor based on a dPIn and dPIn/MWCNT modified screen-printed carbon electrode with a facile method possessed good glucose response. The detectable glucose concentration range covers well the glucose concentrations in urine and blood.

Screen-printed electrode designed with MXene/doped-polyindole and MWCNT/doped-polyindole for chronoamperometric enzymatic glucose sensor

“…S1 . The Mo 3 C 2 -dPIn shows the characteristic peaks of the dPIn at 3284, 1571, and 738 cm −1 corresponding to the N–H stretching, N–H deformation, and out of plane C–H deformation of benzene ring, respectively [ 14 ], as well as the stretching of benzene ring at 1617, 1455, 1214 cm −1 [ 44 ]. The strong absorbance band at 1078 cm −1 is attributed to the dopant ClO 4 ‾ [ 44 ].…”

“…Element contents of the SPCE are carbon, oxygen, chlorine, and silicon. The presence of silicon as a contaminant and the existence of chloride in SPCE imply the components of a carbon ink used [ 14 ]. After the SPCE was coated with Mo 3 C 2 -dPIn, the XPS spectrum shows the new elements of molybdenum and nitrogen which can be attributed to MO 3 C 2 and dPIn, respectively.…”

“…The potential applied was from −0.8 to 0.8 V with the scan rates from 10 to 60 mV/s. To determine glucose responses in several glucose concentrations, chronoamperometry was carried out at +0.6V vs Ag/AgCl within 400 s. The electrochemical cell was incubated in glucose solutions for 3 min before applying a constant potential to the electrochemical system [ 14 ]. The glucose solution (pH 7.4)was prepared a in 0.1 M PBS solution and stored at room temperature for 24 h before use to obtain equilibrium mutarotation between the α and β forms of D-glucose [ 45 ].…”

“…To improve the performances of a glucose sensor, the electrode modification with conductive polymers is promising as it facilitates the glucose oxidase immobilization and the electron transfer from the enzymatic reaction [ 10 ]. The outstanding properties of conductive polymers are tunable optical and electrical properties, compatibility with biological molecules, and simple attachment on the electrode surface by electrochemical polymerization or drop coating [ 13 , 14 ]. Conductive polymers that have been used in glucose sensors were polyaniline [ 10 ], polythiophene [ 15 ], polypyrrole [ 16 , 17 ], polycarbazole [ 18 ], poly (azure A) [ 19 ], and polyindole [ 14 , 20 ].…”

“…The outstanding properties of conductive polymers are tunable optical and electrical properties, compatibility with biological molecules, and simple attachment on the electrode surface by electrochemical polymerization or drop coating [ 13 , 14 ]. Conductive polymers that have been used in glucose sensors were polyaniline [ 10 ], polythiophene [ 15 ], polypyrrole [ 16 , 17 ], polycarbazole [ 18 ], poly (azure A) [ 19 ], and polyindole [ 14 , 20 ]. Polyindole is one of the tunable conductive polymers, its structure comprises of pyrrolytic ring connected with benzene ring.…”