Huang Shipeng, Huang Haicai, Liu Jingqiu, Duan Haoyu, Chen Xi, Chen Houyang
Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China.
Chongqing School, University of Chinese Academy of Sciences, Chongqing, 400714, China.
Mikrochim Acta. 2025 Sep 5;192(10):636. doi: 10.1007/s00604-025-07469-3.
A novel ternary synergistic photoelectrochemical (PEC) probe is presented utilizing metal-organic framework (MOF)-templated Pd/CdS@CoS nanocages for sensing chlorpyrifos (CPF) using chronoamperometry under an applied bias of - 65 mV with 465-nm LED illumination. Derived from ZIF-67 via in situ sulfidation, the hollow nanocage architecture integrated CdS nanoparticles with CoS to form a direct Z-scheme heterojunction, while decorating Pd quantum dots (QDs) created a Schottky barrier, implementing a crucial dual charge-transfer enhancement strategy. Density functional theory (DFT) simulations confirmed a 0.36-eV Fermi level difference at heterojunction interface, verifying a forced built-in electric field. The optimized Pd/CdS@CoS nanocomposite exhibited a remarkable 4.63-fold photocurrent amplification over its pristine CoS, establishing a high-intensity signal baseline essential for accommodating wide-range concentration-dependent signal attenuation. Acetylcholinesterase (AChE)-immobilized biosensor quantified CPF via inhibition-triggered competitive electron consumption to attenuate photocurrent. The sensor demonstrated exceptional performance for CPF detection, most notably featuring a linear dynamic range spanning four orders of magnitude (0.1 ~ 2000 ng·mL). Furthermore, it achieved a low detection limit (0.05 ng·mL, S/N = 3), outstanding specificity against interfering species, excellent long-term stability, and reliable accuracy in complex real water samples (96.5 ~ 104.5%). This study proposes dual charge-transfer enhancement strategy and hollow architecture, addressing the broad-concentration-range in environmental pesticide detection with good sensitivity and adaptability to real-world matrices.
提出了一种新型三元协同光电化学（PEC）探针，该探针利用金属有机框架（MOF）模板化的Pd/CdS@CoS纳米笼，在-65 mV的外加偏压和465 nm LED光照下，采用计时电流法检测毒死蜱（CPF）。通过原位硫化从ZIF-67衍生而来，中空纳米笼结构将CdS纳米颗粒与CoS整合形成直接的Z型异质结，同时修饰Pd量子点（QDs）形成肖特基势垒，实施关键的双电荷转移增强策略。密度泛函理论（DFT）模拟证实了异质结界面处0.36 eV的费米能级差，验证了强制内建电场。优化后的Pd/CdS@CoS纳米复合材料的光电流比其原始CoS显著放大了4.63倍，建立了高强度信号基线，这对于适应宽范围的浓度依赖性信号衰减至关重要。固定有乙酰胆碱酯酶（AChE）的生物传感器通过抑制触发的竞争性电子消耗来量化CPF，从而衰减光电流。该传感器在CPF检测方面表现出卓越的性能，最显著的特点是线性动态范围跨越四个数量级（0.12000 ng·mL）。此外，它实现了低检测限（0.05 ng·mL，S/N = 3），对干扰物质具有出色的特异性，具有优异的长期稳定性，并且在复杂的实际水样中具有可靠的准确性（96.5104.5%）。本研究提出了双电荷转移增强策略和中空结构，以良好的灵敏度和对实际基质的适应性解决环境农药检测中的宽浓度范围问题。
