Dual-parameter cell biosensor for real-time monitoring of effects of propionic acid on neurons

Currently, only a few small devices are capable of continuously recording the physiological states of neurons in real time. Micro-electrode arrays (MEAs) are widely used as electrophysiological technology to detect the excitability of neurons non-invasively. However, the development of miniaturized and multi-parameter MEAs capable of real-time recording remains challenging. In this study, an on-chip micro-electrode and platinum resistor array (MEPRA) biosensor was designed and fabricated to monitor both the electrical and temperature signals of cells synchronously in real time. Such on-chip sensor maintains high sensitivity and stability. The MEPRA biosensor was further used to investigate the effects of propionic acid (PA) on primary neurons. The results demonstrate that PA affects the temperature and firing frequency of primary cortical neurons in concentration-dependent manners. The changes of temperature and firing frequency work in tandem with neuronal physiological status, including neuron viability, intracellular calcium concentration, neural plasticity, and mitochondrial function. This highly biocompatible, stable, and sensitive MEPRA biosensor may provide high-precision reference information for investigating the physiological responses of neuron cells under various conditions.