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Functionalized nanoporous gold as a new biosensor platform for ultra-low quantitative detection of human serum albumin
- Publication Year :
- 2019
-
Abstract
- The development of a new generation of ultra-sensitive sensors for analytical and bio-diagnostic devices requires a strong signal in front of very small quantity of analyte, often present in complex and interfering matrix. Taking advantage of peculiar plasmonic properties of nanoporous gold (NPG), a promising sensor for selective detection of Human Serum Albumin (HSA), a proof-of-concept bioanalyte, was prepared and tested in a conventional micro-Raman spectrometer using Surface Enhanced Raman Spectroscopy (SERS). NPG was synthesized by chemical de-alloying of an amorphous precursor, Au20Cu48Ag7Pd5Si20, starting from melt spun ribbons. A fully de-alloyed ribbon with ligaments of about 60 nm was obtained after 4 h of de-alloying at 70 °C and 10 M HNO3 + 0.5 M HF. This material is self-standing, mechanically resistant, and suitable for wide range of applications. At this stage, NPG is SERS-active toward several molecules, including pyridine, bi-pyridine, and rhodamine at very low concentration. In order to obtain the selective binding properties required to detect molecules in bio-diagnostic applications, immuno-functionalization of NPG was carried out by using an anti-HSA antibody (Ab-anti-HSA) covalently grafted on gold ligaments via the 4-aminothiophenol (4ATP) Raman probe, yielding the SERS-active nanohybrid NPG-4ATP-Ab. SERS signal recorded at increasing HSA concentrations was used for the acquisition of SERS maps and a chemometric regression model allowed to calibrate the sensor. In the best experimental conditions, we were able to get quantitative analysis of HSA at ultra-low concentrations (0.1 ng/l) with SERS. The methodology proposed in this paper has to be considered a major step toward a calibrated device for ultra-sensitive detection of biomolecules by SERS detection.
- Subjects :
- Analyte
Materials science
Nanotechnology
02 engineering and technology
010402 general chemistry
01 natural sciences
Matrix (chemical analysis)
Rhodamine
symbols.namesake
chemistry.chemical_compound
Materials Chemistry
Electrical and Electronic Engineering
Instrumentation
chemistry.chemical_classification
Nanoporous
Biomolecule
Metals and Alloys
Surface-enhanced Raman spectroscopy
021001 nanoscience & nanotechnology
Condensed Matter Physics
0104 chemical sciences
Surfaces, Coatings and Films
Electronic, Optical and Magnetic Materials
chemistry
symbols
0210 nano-technology
Raman spectroscopy
Biosensor
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....f9774ff0f45560d1878e45347bed2ef8