Improved Difenoconazole pesticide detection limit via double-sided porous silicon layers' electrical sensor

Abstract

In this novel work, high-performance laser synthesized double-sided parallel porous silicon layers (Ds-Psi) pesticide sensors were employed. The Ds-Psi layers were synthesized via double beam laser-assisted etching (D-LAE). An easy run, cost-effective and non-poisonous process was adopted to investigate the Ds-Psi sensor performance. This process depended on recording the resonance frequency shift when exposing the pesticides to the sensor's surface. Two configurations were adopted: single-sided Psi sensor of Al/Psi/n c-Si/Al and parallel connected Ds- Psi layer of Al/Psi/c-Si/Psi/Al were synthesized and studied. Under ultra-low concentrations of Difenoconazole pesticide at room temperature, the current-frequency properties of the sensors revealed an excellent response of the Ds-Psi sensor compared with the single-sided Psi sensor. The results of the Ds-Psi sensor showed a much higher sensitivity (82.9%) and a lower detection limit of detection 0.001 ppm. The principal reason for this high performance is effectively related to the high surface area and large capacitance of the parallel configuration of the Ds-Psi layers. The synthesized impedance matching of the parallel configuration is very suitable for quantitative sensing of pesticides.