A novel enzyme based SPR-biosensor to detect bromocriptine as an ergoline derivative drug

In the modern biomedical and therapeutic drug monitoring technology, development of high performance sensing methods for ergoline derivative drug, bromocriptine (BC), is a critical issue due to its plasma low concentration and important function in Parkinson's disease. The results of the protein-ligand docking simulation consistent with competitive inhibition experimental study strongly support the binding of BC to the laccase active site. Therefore, a new biosensor for direct label-free detection of BC is presented based on surface plasmon resonance (SPR) using laccase from Bacillus sp. HR03 as a recognition element. The biosensor chip surface was constructed by covalent immobilization of the laccase on a SPR carboxymethyl dextran surface. The calculated kinetic affinity (KD) was 5.4 nM, which indicated the high affinity between BC and the immobilized laccase. The biosensor could determine BC in a linear detection range from 0.001 ng/ml to 1000 ng/ml with a lower detection limit of 0.001 ng/ml. The biosensor provided acceptable specificity with suitable recovery in simulated blood samples. This new biosensor represents a novel, fast, sensitive, economic cost effective and accurate method for the therapeutic monitoring and detection of the BC.