基于聚苯胺有机半导体发展光电化学体系检测尿素

Development of a photoelectrochemical system based on polyaniline organic semiconductor for detection of urea

聚苯胺(PANI)是一种导电性良好、光电转化效率高的p型有机半导体.采用旋涂法制备了聚苯胺/氧化铟锡(PANI/ITO)电极,然后通过静电吸附将脲酶(urease)固定在PANI/ITO表面,形成Urease/PANI/ITO复合电极.利用脲酶分解尿素(urea)产生的氨可以改变PANI膜质子化状态,从而影响其光电性能的原理,发展可特异性检测尿素的光电化学(PEC)方法.该方法对尿素的线性检测范围较宽(10^(-3)~10^(-8)mol·L^(-1)),特异性、稳定性和可重现性也较好,可用于人体尿液中尿素含量的测定.

Polyaniline(PANI)is a p-type of organic semiconductor with good conductivity and high photoelectric conversion efficiency.In this work,a polyaniline/indium tin oxide(PANI/ITO)electrode was prepared by spin coating.Then,the urease was immobilized on its surface by electrostatic adsorption to form an Urease/PANI/ITO composite electrode.The fixed urease on the surface catalyzes urea decomposition to generate ammonia,changing the PANI film’s protonation state and further affecting itsphotoelectrochemical response.Based on this,a photoelectrochemical(PEC)method for the specific detection of urea was established.The technique has a broad linear detection range for urea(10^(-3)~10^(-8) mol·L^(-1))and has reasonable specificity,stability,and reproducibility.It has been successfully used to detect urea content in human urine.