Fabrication of Aptamer-based Field Effect Transistor Sensors for Detecting Mercury Ions

Abstract

With the rapid development of industry, the pollution of the environment is becoming more and more serious. Among them, water pollution is one of the most serious problems, and polluted water sources often contain heavy metal ions such as mercury, chromium, lead, chromium, arsenic, etc. Which in turn affect our irrigation, breeding, food, and drinking, and finally cause physical harm. Mercury is still widely used today. For example, mercury and mercury compounds are used as catalysts in the plastics industry. Mercury is still widely used today. For example, mercury and mercury compounds are used as catalysts in the plastics industry. Some toxic pesticides also contain mercury. Mercury is used in daily life in fluorescent lamps, batteries, thermometers, medical amalgams, etc. Mercury pollution can be divided into two categories: organic mercury and inorganic mercury. Prolonged exposure to mercury can cause paralysis and a progressive loss of sense of touch, sight, hearing, or taste. Other more common neurological symptoms include memory and balance impairment, insomnia, hand tremors, and behavioral disturbances. Detecting the mercury content in water usually requires large-scale laboratory instruments for measurement, costing a lot of money and time. In this study, a specific aptamer is combined with a field-effect transistor to form an aptamer field-effect transistor by utilizing the properties of thymine-Hg(II)-thymine (T-Hg(II)-T) coordination chemical bonds. A highly selective and sensitive mercury ion sensor was achieved by using N-channel depletion-mode MOSFETs with APTAMER-modified gates. For the Aptamer-modified FET sensor, a detection limit of 0.2 PPM was achieved using a 500 μM × 500 μM gate sensing area. Biosensors realize reduced size, shorter detection speeds, cost savings, and high detection of limit sensors. Therefore, the determination of heavy metal ions in the environment by simple and easy-to-use instruments is of great significance for disease prevention. Figure 1