Flexible biosensor based on signal amplification of gold nanoparticles-composite flower clusters for glucose detection in sweat

Flexible non-invasive glucose monitoring sensor addresses the limitations of intermittent detection and provides the opportunity for optimal therapeutic interventions. However, the low sensitivity of non-invasive sensors restricted their wide applications. In this study, a facile and versatile three-dimensional flexible glucose sensor based on nano-material signal amplification through the structural design and surface modification of sensing electrodes was constructed. Tannic acid-3-aminopropyltriethoxysilane (TA-APTES) coatings were prepared on the activated carbon cloth (aCC) via Michael addition and Schiff base reactions, followed by in situ reductions of gold nanoparticles (AuNPs) to yield AuNPs/TA-APTES/aCC electrodes. Subsequently, glucose oxidases (GOx) were immobilized at the surface of AuNPs to form the sensor. The GOx AuNPs/TA-APTES/aCC sensors exhibit high sensitivity, low detection limit, and fast response rate. The advantage of the GOx AuNPs/TA-APTES/aCC sensors is further illustrated by the excellent stability and the performance in sweat samples with complex components. The design concept of the GOx AuNPs/TA-APTES/aCC for flexible biosensors could potentially drive the development of flexible skin-mountable sensors for monitoring glucose in biofluids.