One-step fluorescence immunochromatographic assay for quantitative detection of adiponectin and leptin.

Adiponectin (ADI) and leptin (LEP) have been proposed as two specific biomarkers of dysfunctional adipose tissue. We aim to establish a one-step time-resolved fluorescence immunochromatographic assay (TRFICA) for simultaneous quantitative detection of ADI and LEP and to evaluate its application value in patients with metabolic syndrome (MS). The TRFICA, using europium(III) (Eu3+) fluorescent microspheres and based on the double-antibody sandwich format, for the quantitative detection of ADI and LEP was individually optimized and established. Subsequently, a dual-target test strip based on TRFICA (TRFICAS) was assembled and evaluated using the clinical samples. The dual-target TRFIAS allows for quantitative detection of serum ADI and LEP within 15 min. Its sensitivity for detecting ADI was 0.01 µg mL-1, and for LEP it was 0.07 ng mL-1, with high specificity. The intra-batch coefficient of variation (CV) and the inter-batch CV were both <11.62%, and recovery ranged from 105.33% to 119.17%. Moreover, strong Pearson correlations were observed between the results measured by the dual-target TRFICAS assay and those obtained from commercial kits (Pearson r = 0.9183 and 0.9051, respectively). Applied to sera from healthy donors and MS patients, the assay clearly distinguished MS patients from the healthy donors. The dual-target TRFICAS has good sensitivity, specificity, precision, a simple procedure, rapid detection and long-term stability, and it is suitable for rapid and quantitative determination of serum ADI and LEP on-site.