Electrochemical Methods for Human Growth Hormone Doping Detection
Human Growth Hormone (GH) is produced by the anterior pituitary gland and promotes growth of tissue through direct uptake at target tissue sites, or alternatively, by regulating production of insulin-like growth factor-1. The World Anti-Doping Agency considers GH a performance enhancing substance, so the use of GH by athletes is prohibited in most sports. The current immunoassay for GH detection is suboptimal for routine screening of blood samples because of the large resources required for collecting, processing, transporting (blood must be shipped to testing sites at controlled temperatures), and testing blood samples.
This study details the development and testing of a novel 96-electrode high-throughput amperometric sensor system to measure GH isoforms in whole blood samples. This high-throughput biosensor system platform reduces the need for sample processing, requires less sample volume, and reduces assay time. The method selectively targets the 22kD and 20kD isoforms of GH, which will provide more statistical discriminatory power than the existing GH test. The present study demonstrate that the amperometric immunosensor assay configuration can detect GH isoforms in 25 µL of whole blood with high linearity (R^2 = 0.98) and a limit of quantitation of 50 pg/mL. This project also describes electrochemical tests to assess the validity of detecting GH from dried blood spots and saliva.