| A photoelectrochemical(PEC)sensor is a new and rapidly developing analytical method,which uses the electron transfer between the photoelectronic material in the excited state and the object to be measured to achieve qualitative or quantitative analysis.It uses light to excite materials with photoelectric activity,and uses electrical signals as the detection signal,so that the excitation and detection signals can be effectively separated.Compared with general electrochemical sensors,the excitation and detection signals of PEC sensors do not interfere with each other,which makes the sensitivity of photoelectrochemical sensors higher.Compared with traditional optical detection instruments,electrochemical detection instruments have lower cost and higher accuracy,which is a promising analytical and detection method.Because of its unique advantages,it has attracted wide attention in different fields such as biomedicine,chemistry,environment and so on.Molecular imprinting technology is a technology for constructing molecularly imprinted polymers with specific recognition sites by introducing template molecules,which is equivalent to the principle of a key and a lock.Molecular imprinting technology has excellent selectivity and stable chemical properties,so it is often used as the recognition center of sensors.The prepared molecularly imprinted photoelectrochemical sensor utilizes the photocurrent generated by the photoelectric material,and can realize the analysis and detection of the target substance.This paper mainly includes the following two parts:A highly sensitive quenching molecular imprinting(MIP)photoelectrochemical(PEC)sensor was proposed to detect acrylamide(AM)by using the photoactive composite of Zn O and polypyrrole(PPy)as the PEC signal probe.A polypyrrole film was formed on the nanodisk Zn O by electrochemical polymerization,and the recognition site of AM was left on the surface of the PPy film by elution,enabling the specific detection of AM.The transfer of electrons will be hindered when AM is adsorbed on the Zn O/PPy nanocomposites surface,which results in the decrease of photocurrent signal.The proposed molecularly imprinted PEC sensor has a wide detection range(10-1 M-2.5×10-9 M),and the lowest detection(LOD)is 2.147×10-9 M(S/N=3).The PEC sensor has excellent selectivity,superior repeatability,preferable stability,low cost,and easy construction,providing a new method for the detection of AM.The high recovery rate in the detection of real samples of potato chips and biscuits indicates that the proposed PEC sensor has potential in monitoring the emerging food safety risks.The one-step solvothermal method was used to synthesize flower-like Cu In S2 and act as light-responsive materials to prepare polydopamine(PDA)nanomaterials with special recognition sites for molecular imprinting during the electrochemical polymerization of dopamine monomers.A signal quenching molecularly imprinted photoelectrochemical sensor was constructed to realize sensitive detection of diazinon(DZN).When DZN is adsorbed on the surface of the molecularly imprinted polymer,the steric hindrance of DZN will hinder the transfer of electrons,increase the electron-hole recombination rate and reduce the photocurrent signal.The results show that the PEC sensor has a wide detection range(10-1 n M-1.0×105 n M),and the lower limit of detection(LOD)is 0.049 n M(S/N=3).The sensor has superior selectivity,excellent stability,good stability,low cost,and easy construction.It has a certain reference for the detection of other pesticides and provides a reference platform for the detection of environmental pollutants. |
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