A powerless, gas-permeable, flexible and transparent carbon micromesh electrode for simultaneous ascorbic acid detection and pH monitoring

Ascorbic acid (AA) is a critical nutrition and chemical for humans, due to its crucial role in metabolic processes and medical treatments. It is necessary to develop a simple and rapid method for real-time tracking AA level in the body. In this work, we fabricated a powerless, gas-permeable, flexible and transparent AA biosensor based on carbon micromesh electrode (CME). The AA biosensor worked without an external power supply and exhibited excellent performances, including high transmittance (>95%), wide detection range (1 mM-1 mM), low limit of detection (10 nM), good selectivity and long-term storage stability (30 days). In addition, we integrated a pH-sensing electrode to correct the AA analysis. A layer of polyaniline (PANI) film was electrodeposited on the carbon micromesh as pH-sensing electrode that had an average sensitivity of 58.1 mV/pH with a high correlation coefficient (R2 1/4 0.997) within the physiological range of human body fluids (pH 4.0-8.7). To verify the availability of the CME in practical application, the Ag/C electrode was used as reference electrode to fabricate the integrated dual -functional biosensors for artificial tears detection. The CME-based biosensors showed good sensitivity, selectivity and correlation coefficient, indicating its excellent practicability towards wearable electronics. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

In this study, a powerless, gas-permeable, flexible and transparent ascorbic acid biosensor based on carbon micromesh electrode was developed. The biosensor showed excellent performances including high transmittance, wide detection range, low limit of detection, good selectivity, and long-term storage stability. By integrating a pH-sensing electrode, the analysis of ascorbic acid can be corrected. The biosensor demonstrated good sensitivity and practicability towards wearable electronics in the detection of artificial tears.