A novel micro-needle sensor based on gold nanoclusters (AuNCs) immobilized with conducting polymer film poly(3,4-ethylenedioxythiophene)-poly(sodium 4-styrenesulfonate) (PEDOT-PSS) was fabricated for determination of iron in coastal waters. The unique aciform structure of the micro-needle electrode (MNE) provided larger specific surface area than common electrodes. The surface modification of MNE with PEDOT-PSS improved the conductivity of the electrode and increased the active sites for combination and immobilization of AuNCs. The cluster-like structure of AuNCs was formed as a result of the regulation of PEDOT-PSS, which showed excellent electrocatalytic activity for the reduction of Fe³⁺. The so-fabricated AuNCs/PEDOT-PSS/MNE showed excellent sensitivity, selectivity, reproducibility, and repeatability for iron determination with the linear range of 0.01–5 μM and detection limit of 3.1 nM, respectively. Furthermore, the micro-needle sensor was successfully used for the determination of acidified dissolved iron in a coastal river from the source to the estuary with satisfactory results.

制备了一种新型的基于金纳米团（AuNCs）的微针传感器，该金针团固定有导电聚合物薄膜聚（3,4-乙撑二氧噻吩）-聚（4-苯乙烯磺酸钠）（PEDOT-PSS），用于测定沿海水体中的铁。微针电极（MNE）的独特的杯状结构提供了比普通电极更大的比表面积。用PEDOT-PSS对MNE进行表面修饰可提高电极的电导率，并增加AuNC结合和固定的活性位点。通过调节PEDOT-PSS形成AuNCs的簇状结构，显示出优异的电催化活性，可还原Fe ³⁺。如此制成的AuNCs / PEDOT-PSS / MNE对铁的测定显示出优异的灵敏度，选择性，可重复性和可重复性，线性范围分别为0.01-5μM和检测限3.1 nM。此外，该微针传感器已成功用于测定从源头到河口的沿海河流中酸化的溶解铁，结果令人满意。