Polypeptide@AuNC probe catalytic amplification-tetramode molecular spectral biosensor for trace Al3

• Published in: Applied surface science 2023-11, Vol.636, p.157797, Article 157797
• Main Authors: Shu, Yiyi, Bai, Hongyan, Li, Chongning, Wen, Guiqing, Liang, Aihui, Jiang, Zhiliang
• Format: Article
• Language: English
• Subjects: Al3; PTAuNC catalysis; SERS quantitative analysis; Tetramode indicator reaction
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2023.157797

A novel tetramode biosensor platform for trace Al3+ based-polypeptide loaded AuNC probe catalytic amplification. [Display omitted] •PTAuNC with recognition and catalytic amplification di-function was prepared.•PTAuNC exhibits strong catalysis of the TMB tetramode indicator reaction.•A new nanocatalytic amplification-tetramode biosensor was established for Al3+.•The method is simple, sensitive and selective. Nanoclusters have strong catalytic effect, but their stability was poor. Biomolecule functionalized gold nanoclusters (AuNC) have attracted extensive attention due to their good biocompatibility, stable physicochemical properties and strong catalytic activity. In this study, the peptide (PT) was used as a template to synthesize the PTAuNC nanoprobe with recognition and catalysis. The results show that PTAuNC has a strong catalytic effect on the indicator reaction of 3,3′,5,5′-tetramethylbenzidine (TMB)–H2O2 to produce the oxidized TMB (TMBox). The TMBox had a strongest fluorescence (FL) peak at 410 nm and an absorption peak at 650 nm. Addition of nanosilver (AgNPs), it produced a strong surface enhanced Raman scattering (SERS) peak at 1616 cm−1 and a resonance Rayleigh scattering (RRS) peak at 370 nm. The new nanocatalytic indicator reaction was organically coupled with the PTAuNC-Al3+ recognition reaction, and a PTAuNC catalytic amplification SERS/RRS/FL/Abs tetramode biosensor platform for Al3+ was constructed. The Al3+ concentration in the range of 0.5–60 nmol/L had a good linear relationship with SERS intensity, with detection limit of 0.21 nmol/L. The method has been applied to the determination of Al3+ in water and food samples. The recovery and relative standard deviation (RSD) were 92.4–109.8% and 1.2–9.8%, respectively.