Constructions And Applications Of Photoelectrochemical Sensors

Photoelectrochemical measurement has been a novel means of detection since1980s, and it has had a rapid development in the past thirty years. Photoelectrochemical sensors are the devices which confirm the object concentration based on the material’s property of light converting to electricity. Light serves as excitation source in the photoelectrochemical sensing system. The electrical signal (current or voltage) is generated by the excitation light separating from excitation light which is detected by some instruments. Photoelectrochemical measurement has been becoming a kind of highly potential analytical method with high sensitivity, simple equipment and easy miniaturization. The main research of this article is to construct photoelectrochemical sensors and its application in the detection of targets. There are mainly two research parts in this article. Part I:Construction and application of Hg+aptamer photoelectrochemical biosensorIt is known that Mercury is one kind of environmental pollutants which is bad to human health and has a bad influence on natural environment. This chapter combines the advantages of photoelectrochemical sensor with the advantages of aptamer to construct a mercury photoelectrochemical biosensor, which shows a performance, such as rapid response, low detection, reliable stability, strong selectivity. The electrode response for mercury ions detection is in the linear range from1×10-14mol L-1to1×10-12mol L"1with the detection limit of3.33×10-15mol L/1. At the same time, this sensor is successfully used to determine Hg2+in tap water, and the result is6.03×10-14mol L-1which is safe for drinking. Part Ⅱ:Construction and application of the glucose photoelectrochemical sensorGlucose plays an important part in the field of biology, which is the energy source and metabolic intermediates for living cells, in other words, it provides lots of energy for creatures. There is important point in detecting glucose fast and accurately in the field of food industry, clinical care, medicine and other fields. This chapter successfully constructs a stably reliable and excellently selective photoelectrochemical glucose sensor, which adopts the CdS electrodeposite ITO sensing beacon and makes detecting trace amounts of glucose in a solution come true. This method combines the catalytic specificity between glucose oxidase and glucose with the advantages of simple, rapid response and excellent sensitivity of photoelectrochemical method. The linear range of the sensor is from3×10-5mol L-1to7×10-4mol L-1with the detection limit of1×10-6mol L-1. Meanwhile the sensor is successfully used to detect the hydrolyzate of sucrose. And the experimental result is satisfactory.