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

As a key biomolecule for neurotransmission, dopamine (DA) is responsible for many neurological syn-dromes. 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 re-vealed 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 mu A mu M-1cm-2), wide linear dynamic range (LDR = 1.0-460 mu M), and reasonably low detection limit (LOD-0.63 mu M). 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. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Dopamine is an important biomolecule for neurotransmission, and effective detection of dopamine is crucial for the rapid diagnosis of neurological disorders. In this study, a non-enzymatic dopamine sensor based on a gold-decorated porous silicon-poly-3-hexylthiophene nanocomposite was designed and characterized. The sensor exhibited excellent sensitivity, a wide linear dynamic range, and a low detection limit, and showed selectivity, reproducibility, and stability in dopamine detection. The gold-decorated nanocomposite-modified electrode may serve as a promising platform for the development of non-enzymatic electrochemical sensors.