Synthesis and Characterization of Bis-1,2,3-Triazole Ligand and its Corresponding Copper Complex for the Development of Electrochemical Affinity Biosensors.

Bistriazole ligand and its corresponding copper complexes were synthesized and characterized for the first time and proposed as new labels for the development of electrochemical aptasensors. The bistriazole ligand was prepared from methyl 1,6-heptadiyne-4-carboxylate and 2-(azidomethyl)phenol using classical CuAAC in presence of different copper salts. X-Ray structure of bistriazole showed a symmetry center (C1). UV-Vis and X-band EPR spectra showed that coordination capacity of bistriazole ligand was improved in presence of triethylamine due to deprotonation of triazole and phenolate moieties. After complexation with copper, the obtained complex was successfully attached to an anti-estradiol aptamer through thiol-maleimide coupling, and the resulting labelled aptamer was immobilized on a carbon screen-printed electrode by carbodiimide coupling. The electrochemical response of the resulting sensor was shown to decrease in the presence of estradiol, demonstrating that the developed complexes can be applied for the development of aptasensors.