Recent Advances in High-Efficiency Perovskite for Medical Sensors

Perovskite materials have considerable potential in medical sensors. This is because the diverse element substitution of the perovskite ABX(3) composition brings rich physical and chemical properties for perovskite materials, including photoelectric conversion, all-optical conversion, and electro-optical conversion. By modifying the A-site, B-site, or X-site elements, the bandgap width of perovskite materials can be adjusted. Moreover, the absorption spectrum, photoelectric conversion electrical signal, and all-optical conversion luminescence spectrum can be regulated in perovskite materials. Perovskite materials also have the advantages of easy fabrication, excellent biocompatibility after modification, variable chemical valence states of constituent elements, and adjustable morphology. Therefore, perovskite materials are expected to be used in medical sensors with different operation mechanisms, such as photoelectric sensors, all-optical conversion sensors, electrocatalytic sensors, physicochemically loading sensors, and surface plasmon resonance (SPR) sensors. Based on the photoelectric conversion mechanism, perovskite medical sensors can detect metabolic substances, cancerrelated substances and drugs in three ways: hindering charge transfer, trapping charges, and changing the number of photo-induced carriers. Furthermore, perovskite photoelectric medical sensors exhibit an ultrasensitive detection performance, even reaching 10(-3) fmol center dot L-1. Based on the all-optical conversion mechanism, metabolite substances and drugs are detected by perovskite all-optical conversion medical sensors via electron/hole transfer, perovskite material degradation, or perovskite material phase transition. Perovskite all-optical conversion medical sensors can be used to detect medical substances based on precise measurement using the photoluminescence spectrum and direct estimation based on the visible color changes. Based on the variable chemical valence states of constituent elements for perovskite materials, metabolite substances, neurotransmitters, cancer-related substances, and drugs are detected by the perovskite electrocatalytic medical sensors via oxidation reaction or reductive reaction. These have variable electrochemical measurement methods for medical substances, such as cyclic voltammetry, amperometry, and differential pulse voltammetry. They can not only simultaneously detect multiple substances but also are biocompatible. Based on the physicochemical loading and SPR mechanisms, metabolite substances and cancer-related substances are detected. Perovskite physicochemically loading medical sensors can detect both liquid and gaseous substances by utilizing the electrical conductivity or adsorbability of perovskite materials, and the detection of perovskite SPR medical sensors will not damage medical substances. In conclusion, owing to the different operation mechanisms of perovskite medical sensors, they exhibit high sensitivity and precision for detecting a wide range of medical substances, which meets the diverse requirements of medical detection. Thus, perovskite medical sensors pave the way for future multidisciplinary integration and development between the medicine and engineering fields.