A dry chemistry-based self-enhanced electrochemiluminescence lateral flow immunoassay sensor for accurate sample-to-answer detection of luteinizing hormone

Colorimetric lateral flow immunoassay (LFIA) is a widely used point-of-care testing (POCT) technology, while it has entered a bottleneck period because of low detection sensitivity, expensive preparation materials, and incapable quantitative detection. Therefore, it is necessary to develop a novel POCT method that is ultrasensitive, simple, portable, and capable of accurately detecting biomarkers in biofluids daily, particularly for pregnancy preparation and early screening of diseases. In this work, a novel dry chemistry-based self-enhanced electrochemiluminescence (DC-SE-ECL) LFIA sensor is introduced for accurate POCT of luteinizing hormone (LH). The proposed DC-SE-ECL immunosensor significantly improves the detection sensitivity through the Poly-l-Lysine (PLL)-based SE-ECL probe and cathode modification of closed bipolar electrode (C-BPE). Additionally, a new type of C-BPE configuration is designed for easily performing the LFIA. And, two standalone absorbent pads are symmetrically arranged below the reporting channel of the electrode pad to decease useless residues on the detection pad, which further improves the detection performance. Under optimized conditions, the proposed LFIA sensor has a low limit of detection (9.274 μIU mL−1) and a wide linear dynamic range (0.01–100 mIU mL−1), together with good selectivity, repeatability and storage stability. These results indicate that the proposed DC-SE-ECL method has the potential as a new tool for detecting biomarkers in clinical samples. [Display omitted] •A novel DC-SE-ECL LFIA sensor was applied for detection of LH.•The sensitivity was greatly improved through the SE-ECL probe and cathode modification.•The LFIA strip was easily fabricated by using various cloth materials.•The portable ECL analyzer was used for rapid immunodetection (about 6 min).•The detection limit was 9.274 μIU mL −1, and the linear range was from 0.01 to 100 mIU mL−1.