Electrochemical biosensing combined with screen-printed paper technology provides an effective strategy for the quantitative analysis of metal ions, particularly suitable for in-situ determination. In this study, a disposable, economical and user-friendly screen-printed dual-working electrodes (SPDEs) aptasensor system for the determination of lead ions (Pb²⁺) and mercury ions (Hg²⁺) was described. The sensor system consists of dual-working electrodes, a counter electrode and a reference electrode fabricated using screen printing technology. The aptasensor demonstrates high sensitivity and selectivity towards Pb²⁺ and Hg²⁺, owing to the larger specific surface area (1334.7 m²/g) and excellent conductivity of mesoporous carbon nanoparticles (MCNs). Additionally, the specific recognition ability and high affinity of G-quadruplex and T-Hg²⁺-T structures for Pb²⁺ and Hg²⁺, respectively, further enhance the performance. Under optimized experimental conditions, the aptasensor achieves a low limit of detection (LOD) of 0.088 ng/mL for Pb²⁺ and 0.0007 ng/mL for Hg²⁺ (S/N = 3), a wide linear range (0.1–1000.0 ng/mL for Pb²⁺ and 0.001–100.0 ng/mL for Hg²⁺), and high accuracy (relative standard deviation, RSD≤10.0 %) and selectivity. Importantly, the SPDEs aptasensor can detect Pb²⁺ and Hg²⁺ in a sample without competition and interference, achieving accuracy comparable to that of commercial inductively coupled plasma mass spectrometry (ICP-MS). These advantages make the SPDEs aptasensor highly suitable for practical applications in environmental monitoring, food safety, and clinical diagnosis.

中文翻译：

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一次性电化学适配体传感器，带有介孔碳球改性丝网印刷双工作电极，用于 Pb2+ 和 Hg2+ 检测


电化学生物传感与丝网印刷纸技术相结合，为金属离子的定量分析提供了一种有效的策略，特别适用于原位测定。在这项研究中，描述了一种用于测定铅离子 （Pb²⁺） 和汞离子 （Hg²⁺） 的一次性、经济且用户友好的丝网印刷双工作电极 （SPDE） 适配传感器系统。传感器系统由双工作电极、对电极和参比电极组成，采用丝网印刷技术制造。由于介孔碳纳米颗粒 （MCN） 具有更大的比表面积 （1334.7 m²/g） 和优异的导电性，该适配传感器对 Pb²⁺ 和 Hg²⁺ 表现出高灵敏度和选择性。此外，G-四链体和 T-Hg²⁺-T 结构分别对 Pb²⁺ 和 Hg²⁺ 的特异性识别和高亲和力进一步增强了性能。在优化的实验条件下，适配传感器实现了 Pb²⁺ 的低检测限 （LOD） 为 0.088 ng/mL，Hg²⁺ 的检测限为 0.0007 ng/mL（S/N = 3），线性范围宽（Pb²⁺ 为 0.1–1000.0 ng/mL，Hg²⁺ 为 0.001–100.0 ng/mL），以及高准确度（相对标准偏差，RSD≤10.0%）和选择性。重要的是，SPDE 适配传感器可以在没有竞争和干扰的情况下检测样品中的 Pb²⁺ 和 Hg²⁺，达到与商用电感耦合等离子体质谱 （ICP-MS） 相当的精度。 这些优势使 SPDE 适配传感器非常适合环境监测、食品安全和临床诊断的实际应用。