Smartphone-operated electrochemical microsensor using carbon nanotube connected NiFe PBA-modified laser induced graphene for on-site glucose sensing

Abstract

Creating high-performance, dependable, and responsive glucose (Glu) sensors is vital for the progress of health monitoring and medical diagnostics. An economical and stable alternative is offered by non-enzymatic electrochemical sensor that use metal-based materials for direct Glu oxidation. Herein, a composite of carbon nanotube (CNT) and FeNi Prussian blue analogs (PBA) was prepared, in which FeNi PBA nanocubes were uniformly linked by CNT to form an interconnected bead-on-a-string network. Then, the FeNi PBA/CNT composite was dropped on an integrated three-electrode system based on laser induced graphene (LIG), forming a novel FeNi PBA/CNT/LIG sensing platform for Glu. The sensor based on FeNi PBA/CNT/LIG could determine Glu from 0.5 & micro;M to 599.5 & micro;M with a high sensitivity of 2.730 & micro;A & micro;M- 1 cm- 2 and a low detection limit of 0.05 & micro;M. Compared with FeNi PBA/LIG and CNT/LIG controls, the FeNi PBA/CNT/LIG sensor exhibits significantly enhanced performance. The observed improvement can be explained by the exceptional properties of each component. Porous LIG forms an ideal substrate with remarkable conductivity and high surface area, facilitating electron transfer. Meanwhile, FeNi PBA/CNT enriches the composite with plentiful active sites, excellent catalytic capability and good conductivity. Subsequently, a portable detection platform integrating a FeNi PBA/CNT/ LIG sensor, a mini electrochemical workstation, and a smartphone was established for the quantitative examination of Glu in food and beverage samples. These results provide a way of developing portable and on-site electrochemical sensors of real-time Glu monitoring.