Emerging organic photoelectrochemical transistors (OPECTs) with inherent amplification capabilities, good biocompatibility and even self-powered operation have emerged as a promising detection tool, however, they are still not widely studied for pollutant detection. In this paper, a novel OPECT dual-mode aptasensor was constructed for the ultrasensitive detection of di(2-ethylhexyl) phthalate (DEHP). MXene/InS/InO Z-scheme heterojunction was used as a light fuel for ion modulation in sensitive gated OPECT biosensing. A transistor system based on poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) converted biological events associated with photosensitive gate achieving nearly a thousand-fold higher current gain at zero bias voltage. This work quantified the target DEHP by aptamer-specific induction of CRISPR-Cas13a trans-cutting activity with target-dependent rolling circle amplification as the signal amplification unit, and incorporated the signal changes strategy of biocatalytic precipitation and TMB color development. Combining OPECT with the auxiliary validation of colorimetry (CM), high sensitivity and accurate detection of DEHP were achieved with a linear range of 0.1 pM to 200 pM and a minimum detection limit of 0.02 pM. This study not only provides a new method for the detection of DEHP, but also offers a promising prospect for the gating and application of the unique OPECT.

中文翻译：

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CRISPR-Cas13a辅助信号放大双模式检测DEHP的有机光电化学晶体管适体传感器

新兴的有机光电化学晶体管（OPECT）具有固有的放大能力、良好的生物相容性甚至自供电操作，已成为一种有前途的检测工具，然而，它们在污染物检测方面尚未得到广泛研究。本文构建了一种新型 OPECT 双模式适体传感器，用于邻苯二甲酸二（2-乙基己基）酯（DEHP）的超灵敏检测。 MXene/InS/InO Z 型异质结被用作敏感门控 OPECT 生物传感中离子调制的光燃料。基于聚（3,4-乙烯二氧噻吩）：聚（苯乙烯磺酸）（PEDOT：PSS）的晶体管系统转换了与光敏栅极相关的生物事件，在零偏置电压下实现了近千倍的电流增益。该工作以靶标依赖性滚环放大为信号放大单元，通过适配体特异性诱导CRISPR-Cas13a反式切割活性来量化靶标DEHP，并结合生物催化沉淀和TMB显色的信号变化策略。结合 OPECT 与比色法 (CM) 的辅助验证，实现了 DEHP 的高灵敏度、准确检测，线性范围为 0.1 pM 至 200 pM，最低检出限为 0.02 pM。该研究不仅为DEHP的检测提供了新的方法，也为独特的OPECT的门控和应用提供了广阔的前景。