Novel Antibody-Free Assay Detects Growth Hormone-Releasing Hormones in Urine

Growth hormone-releasing hormones (GHRHs) are potent peptides that stimulate the release of growth hormone, making them attractive targets for performance enhancement in sports. Accurate and sensitive detection of these substances in biological samples, particularly urine, is critical for anti-doping efforts and potential clinical diagnostics. Traditional detection methods often rely on antibodies, which can be costly, time-consuming to develop, and sometimes lack broad specificity; therefore, there is a significant need for robust, antibody-free methods capable of detecting GHRHs at very low concentrations.

The developed assay demonstrated exceptional analytical performance, achieving the targeted detection of growth hormone-releasing hormones at extremely low concentrations in urine. The method achieved impressive limits of detection (LODs) in the single-digit pg/mL range, specifically between 0.5 pg/mL and 2.5 pg/mL for various GHRH peptides, representing a 2- to 5-fold improvement over many existing antibody-based methods. The assay exhibited excellent linearity across a broad dynamic range, typically from 1 pg/mL up to 1000 pg/mL, with correlation coefficients (R²) consistently above 0.995. Furthermore, the intra-day and inter-day precision were robust, with coefficients of variation (CVs) generally below 10%, and accuracy, assessed through spike-recovery experiments, ranged from 90% to 115%, indicating minimal matrix effects from urine. This high level of sensitivity and specificity ensures reliable detection even for minute amounts of GHRHs.