Functionalized nanoporous gold as a new biosensor platform for ultra-low quantitative detection of human serum albumin

SENSORS AND ACTUATORS B-CHEMICAL

卷:288

Article

Scaglione, F.^1,2  Alladio, E.^1,2  Damin, A.^1,2  Turci, F.^1,2  Baggiani, C.^1,2  Giovannoli, C.^1,2  Bordiga, S.^1,2  Battezzati, L.^1,2  Rizzi, P.^1,2 

[1] Univ Torino, Dipartimento Chim, V Giuria 7, I-10125 Turin, Italy

[2] Univ Torino, NIS, V Giuria 7, I-10125 Turin, Italy

关键词: De-alloying;    Nanoporous gold;    Functionalization;    Human serum albumin;    Selective binding;    Surface Enhanced Raman Spectroscopy;   

DOI  :  10.1016/j.snb.2019.03.005

来源: Elsevier

【 摘 要 】

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 degrees C and 10 HNO3 0.5 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.

【 授权许可】

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