Hybrid nanosensors for biomedical applications

Abstract

In any monitoring system whether industrial or medical, a feedback method is required. This feedback today can be obtained through various nanosensors. Sensors based on semiconductor metal oxides in combination with other materials offer enormous potential in the gas detector industry. The aim of this paper is to present data on the investigated sensors and to discuss their development and application in the medical industry.. TiO2 based sensors are known as time stable hydrogen detectors. However, polymer coatings may improve selectivity parameters and provide new opportunities. Thus, a TiO2 sample coated with a thin layer of PV4D4 has shown potential to be used as a 2-in-1 sensor for detection of biomarkers such as ammonia (kidney failure, liver problems, etc.) and hydrogen (lactose intolerance, digestive tract problems, etc.). These biomarkers are both present in exhaled air, but are also products of food spoilage reactions (meat, canned food, etc.). Heat treatment of the used polymer at 450 °C causes structural changes, resulting in a filtering function that eliminates certain gaseous molecules and improves the hydrogen selectivity of the sensor, achieving responses up to 709%. More recently, results were published regarding the use of PV3D3 and PTFE copolymeric structures, which provide long-term stability of the detector’s selectivity, thus enabling hydrogen detection at different relative humidity, even after 427 days from the initial measurement.