Evaluation of silver substrates for surface-enhanced Raman detection of drugs banned in sport practices

Five different forms of surface-enhanced Raman active silver have been investigated. These forms include colloidal silver prepared by tetrahydroborate or citrate reduction, colloidal silver supported on ion-exchange paper or on cellulose paper and acid etched silver foils. These substrates have been evaluated using nine drugs as model compounds, which are known to be SERS-active on at least one of these substrates. A comparative study of short and long-term signal stability and limits of detection is discussed. The analysis of binary and ternary mixtures of drugs on the different substrates is discussed in terms of adsorptivity and detection power.