基于fl-TiO_(2)/Pt NPs/RuSi NPs的去氧肾上腺素电化学发光传感器的构建和应用

Construction and Application of an Electrochemiluminescence Phenylephrine Sensor Based on fl-TiO_(2)/Pt NPs/RuSi NPs

该文采用溶剂热法制备了高度有序的花状分级二氧化钛微/纳米粒子(fl-TiO_(2)),以(3-氨基丙基)三乙氧基硅烷(APTES)做偶联剂,采用简单的合成后接枝方法制备氨基功能化的fl-TiO_(2)(fl-TiO_(2)-NH_2)。随后,通过静电作用将铂纳米粒子(Pt NPs)组装在fl-TiO_(2)-NH_2表面,制备了一种新型的fl-TiO_(2)/Pt NPs复合材料。最后,将fl-TiO_(2)/Pt NPs与RuSi NPs混合形成均匀的分散溶液,并将其固定在玻碳电极(GCE)表面,制备了一种新型的电化学发光(ECL)传感器(fl-TiO_(2)/Pt NPs/RuSi NPs/GCE)。采用扫描电镜、紫外-可见吸收光谱、X射线衍射和能谱等技术对不同材料的形貌、结构、物理性质和化学组成进行表征,循环伏安法、交流阻抗法和ECL法对所研制ECL传感器的电化学行为和ECL性能进行研究。实验结果表明,Pt NPs优异的电催化活性显著提高了RuSi NPs-三丙胺(TPrA)体系的ECL信号强度。而fl-TiO_(2)的巨大比表面积为Pt NPs和RuSi NPs提供了丰富的结合位点。因此,fl-TiO_(2)/Pt NPs可作为一种新型的共反应剂加速器和ECL信号放大器,用于提高RuSi NPs-TPrA体系的ECL发射效率。在优化实验条件下,fl-TiO_(2)/Pt NPs/RuSi NPs的ECL强度分别为fl-TiO_(2)/RuSi NPs和RuSi NPs的1.5倍和1.8倍。在去氧肾上腺素(PHE)存在下,fl-TiO_(2)/Pt NPs/RuSi NPs-TPrA体系的ECL信号发生猝灭,且ECL猝灭信号与PHE浓度的对数在1.0×10^(-7)~8.0×10^(-5)mol/L范围内呈良好的线性关系(r^(2)=0.998 4),检出限(S/N=3)为2.5×10^(-8)mol/L。该方法用于盐酸去氧肾上腺素注射液中PHE的测定,回收率为99.2%~108%。该传感器具有良好的稳定性和重现性、较高的选择性。该研究为ECL传感平台的构建提供了一种新的ECL信号放大策略,并拓宽了ECL传感器在药物分析中的应用。

Ru(bpy)_(3)^(2+)-doped silica nanoparticles(RuSi NPs),as one of the classical electrochemiluminescence(ECL)luminophores,not only simplify the immobilization process of Ru(bpy)_(3)^(2+),but also effectively improve the utilization rate of Ru(bpy)_(3)^(2+).However,the conductive inertness associated with Si significantly inhibits the electron transfer rate of Ru(bpy)_(3)^(2+),thereby significantly reducing the ECL emission efficiency of RuSi NPs,which,in turn,limits the application of RuSi NPs in ECL sensors.Herein,a kind of highly ordered flower-like hierarchical titanium dioxide micro-nanoparticles(fl-TiO_(2))with a uniform particle size approximately 5.0μm were prepared by a solvothermal method.Furthermore,the amino-functionalized fl-TiO_(2)(fl-TiO_(2)-NH2)was synthesized by a simple post-synthesis grafting method using(3-aminopropyl)triethoxysilane(APTES)as the coupling agent.Subsequently,platinum nanoparticles(Pt NPs)were successfully assembled on the surface of fl-TiO_(2)-NH2 via electrostatic interaction to fabricate a new kind of fl-TiO_(2)/Pt NP composites(fl-TiO_(2)/Pt NPs).Finally,fl-TiO_(2)/Pt NPs/RuSi NPs hybrids were prepared by mixing fl-TiO_(2)/Pt NPs and RuSi NPs in redistilled water to form a uniform dispersed solution,which were immobilized on the surface of glassy carbon electrode(GCE)to develop a novel ECL sensor(fl-TiO_(2)/Pt NPs/RuSi NPs/GCE).The morphologies,structures,physical properties,and chemical compositions of different materials were characterized using techniques such as scanning electron microscopy,UV-Vis absorption spectroscopy,Xray diffraction,and energy spectroscopy.The electrochemical behavior and ECL performance of the proposed ECL sensor were also studied using cyclic voltammetry,alternating current impedance,and ECL techniques.The experimental results suggested that the ECL intensity of RuSi NPs-tripropylamine(TPrA)system enhanced significantly owing to the excellent electrocatalytic activity of Pt NPs,and the large specific surface area of fl-TiO_(2) provided abundant binding sites for Pt NPs and RuSi NPs.Thus,the fl-TiO_(2)/Pt NPs could be used as a novel ECL signal amplifier for enhancing the ECL emission efficiency of RuSi NPs-TPrA system.Under the optimized experimental conditions,the ECL intensity of fl-TiO_(2)/Pt NPs/RuSi NPs was 1.5 and 1.8 times higher than that of fl-TiO_(2)/RuSi NPs and pure RuSi NPs,respectively.Meanwhile,the stable ECL emission from fl-TiO_(2)/Pt NPs/RuSi NPs-TPrA system could be strongly quenched by phenylephrine(PHE).Based on the strong interaction between PHE and RuSi NPs,the designed ECL sensor demonstrated a wide linear range from 1.0×10^(-7) to 8.0×10^(-5) mol/L(r^(2)=0.9984)with a detection limit(S/N=3)of 2.5×10-8 mol/L for PHE,and it was successfully applied to the determination of PHE in phenylephrine hydrochloride injection with excellent long-term stability,good reproducibility,and high selectivity.The recoveries ranged from 99.2%to 108%.This work proposes a novel ECL signal amplification strategy for the construction of ECL sensing platform,which is anticipated to extend the applications of ECL sensors in drug analysis.