Bio-AgNPs-based electrochemical nanosensors for the sensitive determination of 4-nitrophenol in tomato samples: the roles of natural plant extracts in physicochemical parameters and sensing performance

• Published in: RSC advances 2022-02, Vol.12 (1), p.67-617
• Main Authors: Le Nhat Trang, Nguyen, Thi Nguyet Nga, Dao, Hoang, Van-Tuan, Ngo, Xuan-Dinh, Tuyet Nhung, Pham, Le, Anh-Tuan
• Format: Article
• Language: English
• Subjects: Chemistry; Crystal structure; Crystallinity; Green tea; Mathematical analysis; Nanoparticles; Nanosensors; Nitrophenol; Parameters; Particle size distribution; Silver; Tomatoes
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d1ra09202b

The present work reports efficient electrochemical nanosensors for the sensitive monitoring of 4-nitrophenol (4-NP) in tomato samples using various biosynthesized silver nanoparticles (bio-AgNPs). Three different bio-AgNP types were synthesized using natural plant extracts, including green tea (GT) leaf, grapefruit peel (GP), and mangosteen peel (MP), aiming to investigate their effects on the formation of bio-AgNPs, as well as the analytical performance of 4-NP. Based on the obtained results, it was found that the phytochemical content in various plant extracts directly influenced the physicochemical parameters of the created bio-AgNPs, such as particle size, crystallinity, and distribution. More importantly, these parameters have decisive effects on the electrocatalytic activity, conductivity, and electrochemical sensing performance of electrodes modified with them for 4-NP detection. Among the three bio-AgNPs evaluated, the GT-AgNPs (using green tea leaf extract) with uniform shape, small size without aggregation, and high crystallinity showed the best analytical performance for 4-NP determination. The electrode-modified GT-AgNPs exhibited a good 4-NP analytical performance with an electrochemical sensitivity of 1.25 μA μM −1 cm −2 and a detection limit of 0.43 μM in the detection range from 0.5 to 50 μM. The practical applicability of the sensor was also studied in tomato samples, promising satisfactory results toward 4-NP detection in other real samples. In this work, we systematically investigated and compared the electrochemical sensing performances of three electrodes modified with various bio-AgNPs toward 4-NP detection in tomato samples.