ES2.2 - A Frequency-responsive Photoelectric Design for Highly Sensitive Photoelectrochemical Response Measurements
- 17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
- Emerging Systems 2 - Sensing Strategies
- J. Wang, L. Du, W. Chen, C. Wu - Institute of Medical Engineering, School of Basic Medical Science, Health Science Center, Xi'an Jiaotong University, Xi'an (China)
- 314 - 315
A new design derived from light-addressable potentiometric sensors (LAPS) and light-activated electrochemistry (LAE) for highly sensitive photoelectrochemical sensing has been proposed. In this system, a bias voltage is applied to create a depletion layer at the semiconductor/electrolyte interface. A modulated light illuminates the sensor structure to generate electron/hole pairs and causes a detectable alternating photocurrent. The results showed a much higher signal-to-noise ratio (SNR) of the photoelectrochemical response of silicon substrates compared to that using the traditional linear sweep voltammetry (LSV) measurement. Moreover, a pH sensitivity of about 36 mV/pH was obtained analogous to LAPS with a SiO2/Si/electrolyte sandwich structure, but with a steeper photocurrentvoltage curve due to the absence of the insulator layer. The proposed simple and low-cost sensor system can not only be used for photoelectrochemical response measurements of different semiconductors with high SNR, but also be prospective for the sensing of ions, DNA or living cells with spatial reoslution.