Fabrication and application of flexible graphene silk composite film electrodes decorated with spiky Pt nanospheres

Abstract

A free-standing graphene silk composite (G/S) film was fabricated via vacuum filtration of a mixed suspension of graphene oxide and silk fibres, followed by chemical reduction. Spiky structured Pt nanospheres were grown on the film substrate by cyclic voltammetry electrodeposition. The electrical and mechanical performance of a single graphene coated silk fibre was investigated. The conductivity of a single graphene coated silk fibre is 57.9 S m(-1). During 1000 bending measurements, the conductivity was stable and showed negligible variation. The G/S film has a sheet resistivity of 90 Ω □(-1) with a porous and hierarchical structure. The spiky Pt nanosphere decorated G/S film was directly used as a H₂O₂ electrode with a sensitivity of 0.56 mA mM(-1) cm(-2), a linear range of 0-2.5 mM and an ultralow detection limit of 0.2 μM (S/N = 3). A glucose biosensor electrode was further fabricated by enzyme immobilization. The results show a sensitivity of 150.8 μA mM(-1) cm(-2) and a low detection limit of 1 μM (S/N = 3) for glucose detection. The strategy of coating graphene sheets on a silk fibre surface provides a new approach for developing electrically conductive biomaterials, tissue engineering scaffolds, bendable electrodes, and wearable biomedical devices.

Graphene-based fabrics and their applications: a review

“…This is why the use of G derivatives for supercapacitors is on the increase. The same happens in the field of fabrics, where the applications of G materials allows to obtain flexible supercapacitors [61,[69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85]. Fig.…”

“…Liang et al [61] coated silk fiber mats with GO via vacuum filtration. Later GO was reduced to RGO chemically.…”

“…Taking advantage of their high surface area and conductivity, G coated fabrics/fibers have also been employed as sensors for different purposes: electrodes for heart rate monitoring [59], strain sensor [60], H2O2 sensor [61], glucose sensor [61], NO2 gas sensor [62], and acetone and methanol sensor [63].…”

Characterisation of graphene fibres and graphene coated fibres using capacitively coupled contactless conductivity detector

“…In addition, alternative electrically conductive textiles can be made with a variety of fibres including cotton, polyester, and nylon, coated with electrically conductive elements, like carbon, aluminium, copper, gold, or silver. [19][20][21][22] Deposition of gold or other metals on insulating fibres can produce conducting fibres, but also introduces an element of inflexibility, where stretching can easily damage a coating. This is a problem for applications in flexible or wearable devices.…”

“…Carbon offers a promising alternative, particularly graphene, and has been applied in the development of novel conducting composites. 20,21 Following exfoliation from graphite, GO can be adsorbed onto a surface and converted to graphene by chemical reaction using hydrazine, hydroquinone, ascorbic acid, or sodium borohydride. 23 However, adsorption and reduction of GO are critical steps that can drastically affect the final properties of a material or device composed of rGO.…”