An elaborated 3D printing "all-in-one" dual-modal immunoassay (3D-AIO) has been constructed for the colorimetric and photoelectrochemical (PEC) detection of alpha-fetoprotein (AFP), which integrates all step-analysis functional components (including immune/enzyme reaction, separation and detection) together using automatic microfluidics. The released ascorbic acid (AA) from the enzyme-linked immunoreactions can induce the aggregation of gold nanoparticles (AuNPs) by reducing cystine into cysteine, serving as the reporting agent of colorimetric assay. Meanwhile, the released AA induces hole-trapping of the photoactive nanostructured ZnIn2S4 (ZIS), thus triggering a noticeable photocurrent enhancement at ZIS modified screen printed electrode (labeled as ZIS/SPE) slotted in PEC detection chamber. By smart controlling, the colorimetric assays exhibits a distinguishable color change once AFP contents in serum exceed its cut-off value (20 ng mL-1), achieving fast screening and rapid identification purpose for plasma samples as negative or positive, especially in point of care (POC) analysis. And then the PEC immunoassay could be used for more accurate quantitative analysis with the detection limit as low as 0.01 ng mL-1 (S/N = 3). The proposed assay offered bimodal readout for realizing both qualitative fast screening and quantitative PEC determination of AFP concentration, thereby meeting the requirements of quick and precise POC analysis. The direct detection of AFP from human blood makes it promising for on-site POC diagnostics.

中文翻译：

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使用3D打印微反应器设备快速检测AFP的双模式视觉/光电化学多合一生物测定法。

已构建了详细的3D打印“多合一”双模式免疫测定（3D-AIO），用于比色和光电化学（PEC）检测甲胎蛋白（AFP），该蛋白整合了所有分步分析功能组件（包括免疫/酶反应，分离和检测）一起使用自动微流控技术。从酶联免疫反应中释放的抗坏血酸（AA）可通过将半胱氨酸还原为半胱氨酸来诱导金纳米颗粒（AuNPs）的聚集，作为比色测定的报告剂。同时，释放的AA诱导了光敏纳米结构ZnIn2S4（ZIS）的空穴陷阱，从而触发了在PEC检测室中插入的ZIS修饰的丝网印刷电极（标记为ZIS / SPE）的显着光电流增强。通过智能控制，一旦血清中AFP含量超过其临界值（20 ng mL-1），比色测定法就会显示出明显的颜色变化，从而实现快速筛选和快速鉴定血浆样品为阴性或阳性的目的，尤其是在护理点（POC）分析。然后，PEC免疫测定可用于更准确的定量分析，检测限低至0.01 ng mL-1（S / N = 3）。所提出的测定法提供了双峰读数，可实现定性快速筛选和定量PEC测定AFP浓度，从而满足快速精确POC分析的要求。从人血中直接检测AFP使其有望用于现场POC诊断。实现对血浆样品为阴性或阳性的快速筛选和快速鉴定的目的，尤其是在即时护理（POC）分析中。然后，PEC免疫测定可用于更准确的定量分析，检测限低至0.01 ng mL-1（S / N = 3）。所提出的测定法提供了双峰读数，可实现定性快速筛选和定量PEC测定AFP浓度，从而满足快速精确POC分析的要求。从人血中直接检测AFP使其有望用于现场POC诊断。实现对血浆样品为阴性或阳性的快速筛选和快速鉴定的目的，尤其是在即时护理（POC）分析中。然后，PEC免疫测定可用于更准确的定量分析，检测限低至0.01 ng mL-1（S / N = 3）。所提出的测定法提供了双峰读数，可实现定性快速筛选和定量PEC测定AFP浓度，从而满足快速精确POC分析的要求。从人血中直接检测AFP使其有望用于现场POC诊断。所提出的测定法提供了双峰读数，可实现定性快速筛选和定量PEC测定AFP浓度，从而满足快速精确POC分析的要求。从人血中直接检测AFP使其有望用于现场POC诊断。所提出的测定法提供了双峰读数，可实现定性快速筛选和定量PEC测定AFP浓度，从而满足快速精确POC分析的要求。从人血中直接检测AFP使其有望用于现场POC诊断。