Black phosphorus-based field effect transistor devices for Ag ions detection*

Black phosphorus (BP), an attractive two-dimensional (2D) semiconductor, is widely used in the fields of optoelectronic devices, biomedicine, and chemical sensing. Silver ion (Ag+), a commonly used additive in food industry, can sterilize and keep food fresh. But excessive intake of Ag+ will harm human health. Therefore, high sensitive, fast and simple Ag+ detection method is significant. Here, a high-performance BP field effect transistor (FET) sensor is fabricated for Ag+ detection with high sensitivity, rapid detection speed, and wide detection concentration range. The detection limit for Ag+ is 10−10 mol/L. Testing time for each sample by this method is 60 s. Besides, the mechanism of BP-FET sensor for Ag+ detection is investigated systematically. The simple BP-FET sensor may inspire some relevant research and potential applications, such as providing an effective method for the actual detection of Ag+, especially in witnessed inspections field of food.