Electrochemical behavior of palladium nanoparticles deposition on glassy carbon electrode from reline and ethaline and its application in DNA sensors

In this study, we investigate the electrochemical behavior of palladium nanoparticles (PdNP) deposition on glassy carbon electrode (GCE) in two deep eutectic solvents, namely, reline and ethaline, and its application in DNA sensors. The electrochemical behaviors of PdNP deposition are investigated by cyclic voltammetry and chronoamperometry. The obtained results indicate that the PdNP deposition on GCE in reline was dominated by the progressive 3D nucleation mechanism, while that in ethaline was dominated by the instantaneous nucleation mechanism. The structural, morphological, and compositional characteristics are also investigated through X-ray diffraction, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. A PdNP-based DNA sensor is constructed for Mycobacterium tuberculosis detection. Results indicate a significant difference between the DNA sensing responses based on the PdNPs synthesized in reline (PdNP-RE) and ethaline (PdNP-ET). The PdNP-ET–based DNA sensor has higher sensitivity than the PdNP-RE–based DNA sensor. This study serves as a reference for the development of improved nanomaterials for bioanalysis and the elaborate design of biosensors for practical applications.