Paper-based microfluidic device for selective detection of peanut allergen Ara h1 applying black phosphorus-Au nanocomposites for signal amplification

This paper developed a portable microfluidic paper-based analysis device (μ-PAD) combined with the electrochemical technique for efficient and sensitive detection of peanut allergen Ara h1. The proposed μ-PAD works based on the variation of differential pulse voltammetry (DPV) response current induced by peanut allergen Ara h1. Black phosphorus (BP)–Au nanocomposites were introduced both to improve the electron transfer rate at the electrode interface for signal amplification, and to immobilize the specific Ara h1 aptamers through Au–S bonding to recognize the target in food matrices. This μ-PAD had good specificity and detection stability for Ara h1 allergen and could complete the entire analysis process within 20 min, achieving a wide linear response range (25–800 ng mL−1) and a low detection limit (LOD, 11.8 ng mL−1). In the Ara h1 allergen detection applied to real peanut products (cookies, milk, and bread), the constructed μ-PAD obtained acceptable recoveries (93.50%–101.86%) with relative standard deviations (RSDs) of 0.36–2.97% (n = 3), with a good correlation with the ELISA results (R2 = 0.9956). Therefore, the portable μ-PAD based on BP-Au nanocomposites was demonstrated to provide an effective strategy for rapid analysis and screening of Ara h1 allergen in food, which has broad application prospects.