Self-Powered Biosensors Using Various Light Sources in Daily Life Environments: Integration of p-n Heterojunction Photodetectors and Colorimetric Reactions for Biomolecule Detection.

Electronic biosensors operating without power supply are high in demand owing to increasing interest in point-of-care (POC) coupled with portable and wearable electronic devices for smart healthcare services. Although self-powered electronic sensors have emerged with the promise of resolving the energy supply problems, achieving sufficient sensitivity to targets in real samples is highly challenging because of the matrix effect caused by electroactive species. In this study, we developed a self-powered biosensor platform by combining n-indium gallium zinc oxide (IGZO)/p-Si heterojunction photodetectors and physically separated colorimetric reactions. The self-powered biosensors were applied to glucose detection in real human samples using light sources from daily life environments such as fluorescent light and sunlight. The sensors showed high sensitivity and stability from 0.01 to 10 mg mL-1 of glucose in human saliva and urine without matrix effect from the electroactive species in real samples. In addition, a small change in glucose concentration in human serum was distinguishable with a resolution of 0.01 mg mL-1. Notably, these results were obtained using well-developed and widely used materials like Si and IGZO with simple deposition techniques. Moreover, this self-powered biosensing platform can be universally applied for the detection of all biomolecules being detected by colorimetric assays. To the best of our knowledge, this is the first report on such self-powered biosensors, which could be a promising candidate for future POC biosensors integrated with portable and wearable electronic devices.