SERS spectral study of HAuCl4-cysteine nanocatalytic reaction and its application for detection of heparin sodium with label-free VB4r molecular probe

A novel peptide electrochemical biosensor for heparin based on the dual "turn-on" signals of Ag/2D CuTCPP(Fe)

Herein, a "turn-on" peptide-based electrochemical biosensor was developed for the dual-signal sensing of heparin employing Ag/2D CuTCPP(Fe). Our method with high analytical performance was exploited in the accurate quantification of heparin in rat serum throughout its metabolic process.

A new SERS strategy for quantitative analysis of trace microalbuminuria based on immunorecognition and graphene oxide nanoribbon catalysis

Background

Microalbuminuria (mAlb) detection is essential for the diagnosis and prognosis of nephrotic patients and hypoproteinemia. In this article, we develop a new surface-enhanced Raman scattering (SERS) quantitative analysis method to detect mAlb in urine.

Methods

Combined the mAlb immunoreaction with gold nanoreaction of graphene oxide nanoribbons (GONR)-HAuCl₄-H₂O₂, and used Victoria blue B (VBB) as molecular probe with a SERS peak at 1,615 cm⁻¹, a new SERS strategy for quantitative analysis of trace mAlb in urine was established.

Results

The linear range of SERS quantitative analysis method is from 0.065 to 2.62 ng/mL, with a detection limit of 0.02 ng/mL. The SERS method was applied to analysis of mAlb in urine with good accuracy and reliability, the relative standard deviation is 0.49%–2.28% and the recovery is 96.9%–109.8%.

Conclusion

This study demonstrated that the new SERS quantitative analysis method is of high sensitivity, good selectivity and simplicity. It has been applied to analysis of mAlb in urine, with satisfactory results.

A simple and sensitive SERS quantitative analysis method for urea using the dimethylglyoxime product as molecular probes in nanosilver sol substrate

Under the light wave irradiation, the stable and highly surface enhanced Raman scattering (SERS) active silver nanosol (AgNP) was prepared by reduction of AgNO₃, using sodium citrate as reducer. Urea reacted with dimethylglyoxime to produce 4,5-dimethyl-2-imidazole ketone that exhibited a strong SERS peak at 1320 cm^-1 in the as-prepared AgNPs substrate. Under the selected conditions, the increased SERS intensity ΔI was linear to urea concentration in the range of 8.25-825 nM, with a detection limit of 4.92 nM. Accordingly, a new, simple SERS quantitative analysis method for trace urea in foods was established, with relative standard deviation of 0.92-4.8% and recovery of 97.4-101%.