Quantitative immunochromatographic assay for rapid and cost-effective on-site detection of benzo[a]pyrene in oilfield chemicals

Contamination of oilfield chemicals (OFCs) by benzo[a]pyrene (B[a]P) is increasingly becoming a severe environmental security issue. There is an urgent need to develop a rapid and accurate method for B[a]P detection in OFCs. In this study, B[a]P hapten was designed using computer aided molecular design. A high-affinity, specific, and matrix-insensitive monoclonal antibody (mAb) with IC50 values of 6.77 ng/mL was obtained. Based on this mAb, we developed a rapid gold nanoparticle-based immunochromatographic strip assay (GICA) with double T-line mode for on-site detection of B[a]P in OFCs samples. The GICA exhibited excellent detection performance in OFCs samples with strong acidity, strong alkalinity, and deep color. Under optimal conditions, the proposed method detected B[a]P in OFCs at 0.42–300 mg/kg, and limit of detection was 0.23–1.07 mg/kg. The recovery rate was 88%–106% with a coefficient of variation of 1.46%–6.35%. Confirmed by natural positive OFCs samples and high-performance liquid chromatography, this GICA is accurate and reliable, with great potential for rapid and cost-effective on-site detection. In the oilfield industry, environmental protection requirements are increasingly strict and green development is advocated. The use of Contamination of oilfield chemicals (OFCs) runs through the whole process of oil and gas exploration and development, so it is essential to strengthen the supervision of the use of OFCs. However, there is currently no universally accepted method for detection of B[a]P in OFCs samples. In this work, based on anti-B[a]P specific mAb preparation, we developed a highly sensitive and specific GICA with double T-line mode for on-site detection of B[a]P in OFCs samples.