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

Abstract

In the presence of nanocatalyst, L-cysteine reduce HAuCl4 rapidly to form gold nanoparticles (AuNP), and a quick nanocatalytic preparation procedure was established for Au/AuNP sol with highly active surface enhanced Raman scattering (SERS) effect and good stability. The nanoreaction was also studied by absorption, resonance Rayleigh scattering (RRS), transmission electron microscopy (TEM) and energy spectra. In the selected conditions, the analyte heparin sodium (HS) could react with victoria blue 4 R (VB4r) to form associated complexes which have very weak SERS effect to make the SERS signals decrease. The SERS signals at 1617 cm−1 reduced linearly with HS concentration increasing. Upon addition of FeCl3, it hydrolyzed to form stable Fe(OH)3 sol platform that carried SERS active Au/AuNPs to enhance the sensitivity. Accordingly, we established a SERS quantitative analysis method in the sol substrate of Fe(OH)3-Au/AuNPs, with a linear range of 0.5–75 ng/mL HS and a detection limit of 0.2 ng/mL. HS in real samples was determined, with a relative standard deviation of 2.65–7.63% and a recovery of 99.3–101%.

Microplasma-printed Au-based SERS sensing platform for ultra-sensitive chemical analyte detection

“…Considering AgNPs are easily oxidized and less stable than AuNPs, AuNP-based platforms were chosen as the target products. 20 Besides, it is reported that dielectric materials can localize electric fields by multiple scattering of light. 21 When AuNPs are assembled with dielectric materials, surface plasmon of AuNPs and their electric dipoles are simultaneously generated upon exposure to light.…”

Enzyme-free Gold-silver Core-shell Nanozyme Immunosensor for the Detection of Haptoglobin

“…Recent research has looked into the development of novel detection methods coupled with nanozymes. 50,51 In this study, an immunosensor was developed using silver nanoparticles as the nanozyme instead of the biological enzyme using a simple one-step synthesis of silver nanoparticles deposition. Gold nanoparticles were used as the seed platform and to enhance the sensitivity of the sensor by increasing the surface area for seeding of silver nanoparticles, as well as for the conjugation of detecting antibodies, which will result in a higher likelihood of detecting the target protein.…”

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

“…16 Generally, SERS signal depends upon a number of factors. However, the substrateadsorbed molecular probe can greatly amplify the signals and it is linear to the SERS signal at some certain conditions, 17,18 and an SERS method can be developed for the detection of the molecular probe. Javier and Ronei 17 studied a paper-based portable SERS method for the detection of uric acid, with an LR of 0-3.5 mmol/L and a DL of 0.11 mmol/L.…”

“…Javier and Ronei 17 studied a paper-based portable SERS method for the detection of uric acid, with an LR of 0-3.5 mmol/L and a DL of 0.11 mmol/L. Wang et al 18 used the catalytic activity of GO to catalyze the H 2 O 2 -HAuCl 4 system, and then ligands regulated the use of SERS to detect human chorionic gonadotropin, and Hg 2+ in concentrations ranging from 0.25 to 10 ng/mL, 0.25-10 nmol/L, was tested on samples which showed good recovery. Frost et al 19 developed a SERS sensor based on citrate-functionalized AuNP for 50-1,000 ng/L Pb 2+ .…”