A novel gold-decorated porous silicon-poly(3-hexylthiophene) ternary nanocomposite as a highly sensitive and selective non-enzymatic dopamine electrochemical sensor

Abstract

As a key biomolecule for neurotransmission, dopamine (DA) is responsible for many neurological syndromes. Hence, effective DA detection is vital for the rapid-diagnosis of diseases caused by irregular DA levels. Therefore, we designed a non-enzymatic DA sensor using the novel gold-decorated porous silicon-poly-3-hexylthiophene (Au@PSi-P3HT) nanocomposite fabricated glassy carbon electrode. We employed a simple stain etching technique followed by ultra-sonication and photo-reduction techniques to synthesize this novel Au@PSi-P3HT nanocomposite. The structural, morphological, and surface characterizations of the Au@PSi-P3HT nanocomposite were performed using various analytical tools. TEM and FESEM images revealed that gold nanoparticles were randomly dispersed onto the PSi-P3HT sheet-like structure. In the electrochemical investigations, the Au@PSi-P3HT/GCE sensor showed excellent sensitivity (0.5112 μAμM−1cm−2), wide linear dynamic range (LDR = 1.0–460 μM), and reasonably low detection limit (LOD ∼0.63 μM). This newly designed DA sensor was also employed to check the potential chemical interference using several common biomolecules and the obtained results confirmed its selectivity during DA detection. The Au@PSi-P3HT/GCE sensor also exhibited satisfactory results in detecting DA levels in human blood serum and dopamine hydrochloride injection samples. Besides, the Au@PSi-P3HT/GCE sensor displayed superb reproducibility, repeatability, and stability. This novel Au@PSi-P3HT nanocomposite-modified GCE may emerge as a successful means for further designing effective non-enzymatic electrochemical sensors.