辉钼矿熔融盐抗坏血酸传感器制备及性能研究

Study on preparation and performance of ascorbic acid sensor modified with molybdenite based molten salt

以天然辉钼矿MLN和铜纳米粒子为原材料,在450℃条件下,LiCl-KCl为熔盐介质,采用熔融盐方法合成了MLN/Cu复合材料,并用场发射扫描电镜(FE-SEM)、X射线衍射(XRD)等方式对该材料进行了表征,该材料长10~2000 nm,宽5~1500 nm,比天然MLN材料具有更高的电导率和更大的表面积。用MLN/Cu材料修饰的玻碳电极(GCE)构建的电化学传感器,能够实现对抗坏血酸(AA)的特异性检测,检测AA线性范围为3~3000μmol/L,灵敏度为42.64μA·(mmol/L)^-1·cm^-2,检测限(S/N=3)为0.02μmol/L,响应速度为1.89 s。此外,MLN/Cu/GCE传感器对AA具有良好的专一选择性,避免了其他结构相似的化合物(如尿酸、多巴胺、葡萄糖、果糖、H2O2)和常见金属离子(K^+、Mg^2+、Na^+)的干扰。

A conductive molten salt was synthesized by using natural molybdenite(MLN)and copper nanoparticles(Cu)at 450℃using KCl and LiCl as solvents.The molten salt(MLN/Cu)was used directly as a sensor material to determine ascorbic acid(AA).As prepared MLN/Cu were 10~2000 nm long and 5~1500 nm wide,and possessed higher conductivity and larger surface area than natural MLN.The prepared sensor exhibits very high sensitivity of detection AA of 42.64μA(mmol/L)^-1 cm^-2 under the concentration ranging from 3 to 3000μmol/L,and a detection limit of approximately 0.02μmol/L(S/N=3),and a rapid current response(1.89 s).In addition,the MLN/Cu/GCE sensor exhibits excellent selectivity to AA,which avoid the interference from other structurally similar compounds(e.g.uric acid,dopamine,glucose,fructose,H2O2),and common metal ions(K^+,Mg^2+,Na^+).The approach is considered to provide a sensitive,selective,and reliable tool for highly detection of AA.