It is desired and urgently needed to improve the sensitivity of immunochromatography assay (ICA) for hazardous chemicals. In this work, an enhanced ICA strip was established and evaluated for simultaneous, semi-quantitative and quantitative detection of ochratoxin A (OTA) and aflatoxin B₁ (AFB₁). The signal strategy based on gold growth on the surface of the E. coli K12 carrier was recommended, which was successfully self-assembled on the enhanced ICA with a double test line pattern. When used as a novel carrier, the E. coli K12 could provide a larger surface area, better biocompatibility and high loading capacity, which was of great help to improve the performance of the ICA. By the naked eye, the semi-quantitative limit of detection (semi-Q-LOD) reached 0.03 ng/mL for both OTA and AFB₁ (17-fold and 33-fold lower than the conventional ICA strip). By the digitized strip reader, the quantitative LODs (Q-LODs) were all identified as 0.01 ng/mL for two mycotoxins (10-fold improvement), with detection ranges of 0.01–0.5 ng/mL for OTA and 0.01–0.2 ng/mL for AFB₁. Furthermore, the high reliability and applicability of the ICA were confirmed by its good correlation with liquid chromatography-tandem mass spectrometry (LC-MS/MS). The advantages of the improved sensitivity, high efficiency and cost savings had been reflected for the ICA. This study could provide an important reference method for the sensitive, simultaneous, rapid and on-site monitoring of multicomponent contaminants.

提高免疫色谱法 (ICA) 对危险化学品的灵敏度是迫切需要的。在这项工作中，建立并评估了增强的 ICA 条带，用于同时、半定量和定量检测赭曲霉毒素 A (OTA) 和黄曲霉毒素 B ₁ (AFB ₁ )。推荐了基于大肠杆菌K12载体表面金生长的信号策略，成功自组装在具有双测试线图案的增强型ICA上。当用作新型载体时，大肠杆菌K12可以提供更大的表面积、更好的生物相容性和高负载能力，这对提高ICA的性能有很大帮助。通过肉眼，OTA 和 AFB ₁的半定量检测限 (semi-Q-LOD) 均达到 0.03 ng/mL （比传统 ICA 试纸低 17 倍和 33 倍）。通过数字化条带阅读器，两种霉菌毒素的定量 LOD (Q-LOD) 均确定为 0.01 ng/mL（提高 10 倍），OTA 的检测范围为 0.01-0.5 ng/mL，而 OTA 的检测范围为 0.01-0.2 ng/mL。 AFB _1的毫升. 此外，ICA 的高可靠性和适用性通过其与液相色谱-串联质谱 (LC-MS/MS) 的良好相关性得到证实。提高灵敏度、提高效率和节省成本的优势已在 ICA 中得到体现。该研究可为多组分污染物的灵敏、同步、快速和现场监测提供重要的参考方法。