Oliveira Igor G S, Gallina Fernando C, Affonso Muriel R, Souto Robson S, Lanza Marcos R V, Martelli Silvia M, Barros Willyam R P
Federal University of Grande Dourados - UFGD, Rodovia Dourados-Itahum, km 12, Dourados, MS, 79804-970, Brazil.
São Carlos Institute of Chemistry, University of São Paulo, Av. João Dagnone, 1100, São Carlos, SP, 13563-120, Brazil.
Mikrochim Acta. 2025 Apr 28;192(5):325. doi: 10.1007/s00604-025-07177-y.
The development and application of a highly sensitive electrochemical screen-printed electrode (SPE) for the determination of folic acid (FA) is presented. The SPE was fabricated on a polyethylene substrate using customized graphite ink and modified with Printex L6 carbon (PL6C) dispersed in chitosan (Chi). Gold (Au) nanoparticles were electrodeposited onto the SPE surface, followed by electropolymerization of polyaniline (PAni) in a deep eutectic solvent (DES), enhancing the electrochemical performance. The modified PAni-DES/Au/PL6C@Chi/SPE was characterized using cyclic voltammetry and differential pulse voltammetry in 0.1 mol L⁻ Britton-Robinson buffer solution at pH 7.0. Compared to the bare SPE, the modified sensor showed a significantly enhanced current response for FA detection, with a linear dynamic range of 1.15 to 40.00 μmol L⁻ (R = 0.998) and a limit of detection (LOD) of 0.018 μmol L⁻. The sensor was successfully applied to real samples such as saliva, blood serum, and urine, exhibiting high sensitivity with recovery between 95.25% and 103.80%. It also demonstrated excellent selectivity against common interferents, and the fully lab-made platform offers competitive performance compared to conventional systems, highlighting its innovative design and potential for customization. The absence of a significant memory effect and minimal matrix interference further underscore the sensor's reliability for clinical diagnoses and quality control analyses. Additionally, the sensor is cost-effective and requires low reagent and sample consumption, making it a promising alternative for practical applications.
本文介绍了一种用于测定叶酸（FA）的高灵敏度电化学丝网印刷电极（SPE）的开发与应用。该SPE是在聚乙烯基底上使用定制石墨油墨制成，并采用分散于壳聚糖（Chi）中的普林特克斯L6碳（PL6C）进行修饰。将金（Au）纳米颗粒电沉积到SPE表面，随后在深共熔溶剂（DES）中对聚苯胺（PAni）进行电聚合，从而提高电化学性能。在pH 7.0的0.1 mol L⁻ Britton-Robinson缓冲溶液中，使用循环伏安法和差分脉冲伏安法对修饰后的PAni-DES/Au/PL6C@Chi/SPE进行表征。与裸SPE相比，修饰后的传感器在检测FA时显示出显著增强的电流响应，线性动态范围为1.15至40.00 μmol L⁻ （R = 0.998），检测限（LOD）为0.018 μmol L⁻ 。该传感器成功应用于唾液、血清和尿液等实际样品，具有高灵敏度，回收率在95.25%至103.80%之间。它还对常见干扰物表现出优异的选择性，与传统系统相比，全实验室自制的平台具有竞争性能，突出了其创新设计和定制潜力。不存在明显的记忆效应和最小的基质干扰进一步强调了该传感器在临床诊断和质量控制分析中的可靠性。此外，该传感器具有成本效益，试剂和样品消耗低，是实际应用中有前景的替代方案。
