A label free, signal off electrochemical aptasensor for amphetamine detection

Prescription stimulant drug (PSD) abuse is a worldwide concern, as they are clinically prescribed for psycho-logical conditions and can be consumed recreationally without supervision. Easy accessibility of PSD procurement is also affecting the incidence of drug addiction among young and adult populations. Hence, there is a great need for the development of sensitive, rapid, and low-cost kits for on-spot PSD detection. In this study, a gold nanoflower modified, electrochemical aptasensor was constructed for Amphetamine (AMP) detection. The aptasensor was developed by covalent immobilization of thiolated AMP-specific aptamers (AMP-Apt) on AuNFs as a sensing interface. This configuration also enhanced aptamer density (6.37 +/- 0.31 x 10(12) molecules/cm2) on the electrode and low limit of detection of 0.51 nM in the linear range of 0.1-1.0 nM and sensitivity 0.501 nM/ mu A. The effect of potentially interfering compounds on the determination of AMP was found to be negligible for biological molecules and chemical entities. The aptasensor was successful in detecting AMP spiked urine and water samples with a recovery of 99-104% and 94.3-105% respectively. To our knowledge, this is the first label -free, gold nanoflowers modified electrochemical aptasensor for AMP detection and can be adapted for testing potential PSDs in the future.