Spectrophotometric determination of epinephrine using new analytical systems based on label-free silver triangular nanoplates

Silver triangular nanoplates (AgTNPs) is a promising and still relatively poorly studied colorimetric probe for sensing various organic compounds. In particular, they undergo a change in their morphology when interacting with various catecholamines. This process is accompanied by a hypsochromic shift of the local surface plasmon resonance (LSPR) band of nanoparticles. The greatest spectral changes can be observed in the case of the interaction of AgTNPs with epinephrine which can be the basis for a sensitive method for its detection. It was found that the detection limit of epinephrine under the selected optimal conditions is equal to 3 uM, and the dynamic range is from 9 uM up to 50 uM. Selectivity of the proposed method for the epinephrine determination was evaluated as well. It was shown that the determination does not interfere with a 10-fold excess of vanillylmandelic acid and dopamine, and with a 1000-fold excess of common cations and anions. The proposed approach was successfully applied to the determination of epinephrine in a drug and a sample of artificial urine containing an epinephrine additive.