基于Au@N-CDs纳米复合材料电化学传感器检测左氧氟沙星

An Electrochemical Sensor Based on Au@N-CDs Nanocomposite for Determination of Levofloxacini

本文以富氮生物物质为前驱体合成氮掺杂碳点(N-CDs),调控反应时混合溶液pH值,协同发挥N-CDs还原性和稳定性效应,还原HAuCl_(4)生成并稳定Au纳米粒子(AuNPs),以水浴孵化法制备Au@N-CDs纳米复合材料。基于AuNPs良好电催化能力,N-CDs高比表面积和对左氧氟沙星(LEV)亲合力,提高玻碳电极(GCE)对LEV检测的选择性和灵敏度。在pH=6.0磷酸盐缓冲溶液中,于电位0.4V下富集125s,Au@N-CDs/GCE可在利福平、罗红霉素、红霉素等抗生素共存情况下选择性检测LEV,检出限和线性范围分别为1.0×10^(-6) mol/L和2.5×10^(-6)~1.0×10^(-4) mol/L。该法成功应用于人体尿样中LEV测定,回收率为93.0%~107.4%,相对标准偏差为2.98%。

Pharmaceutical antibiotics contaminants are harmful to hydrosphere and biosphere, especially levofloxacin(LEV) which is the most consumed pharmaceutical antibiotic.Nitrogen-rich biomass materials were prepared by using Nitrogen-doped carbon dots(N-CDs) as precursor, and reducibility and stability of N-CDs were controlled by changing the reaction pH value.A novel electrochemical sensor was developed for levofloxacin(LEV) by the prepared Au@N-CDs nanocomposites under water bath incubation, which was to reduce HAuClto form and stabilize Au nanoparticles(AuNPs) to solve the problem of AuNPs agglomeration.The good electrocatalytic ability of AuNPs, high specific surface area of CDs and affinity for LEV were found to offer high selectivity and sensitivity of glassy carbon electrode(GCE) for LEV in mixed samples, and the sensor was successfully used in the analysis of the LEV in synthetic urine, with recovery values of around 93.0%-107.4% and RSD of 2.98%.The detection limit was 1.0×10^(-6)mol/L and the linear range was 2.5×10^(-6)-1.0×10^(-4)mol/L for LEV with the co-existence of other antibiotics such as rifampicin, roxithromycin and erythromycin.