1. Ultrasensitive SERS immunoassay based on diatom biosilica for detection of interleukins in blood plasma
- Author
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Agnieszka Kamińska, Tomasz Szymborski, Katarzyna Winkler, and Myroslav Sprynskyy
- Subjects
Medical diagnostic ,Nanoparticle ,Metal Nanoparticles ,Nanotechnology ,02 engineering and technology ,Biosensing Techniques ,Interleukin 8 ,010402 general chemistry ,Spectrum Analysis, Raman ,01 natural sciences ,Biochemistry ,Analytical Chemistry ,Limit of Detection ,Blood plasma ,medicine ,Humans ,Surface-enhanced Raman spectroscopy (SERS) ,Detection limit ,Immunoassay ,Diatoms ,medicine.diagnostic_test ,Chemistry ,Interleukin-8 ,Interleukin ,Reproducibility of Results ,021001 nanoscience & nanotechnology ,Silicon Dioxide ,0104 chemical sciences ,Specific antibody ,Diatom biosilica ,Colloidal gold ,Gold ,0210 nano-technology ,Research Paper - Abstract
An ultrasensitive surface-enhanced Raman scattering (SERS) immunoassay based on diatom biosilica with integrated gold nanoparticles (AuNPs) for the detection of interleukin 8 (IL-8) in blood plasma has been developed. The SERS sensing originates from unique features of the diatom frustules, which are capable of enhancing the localized surface-plasmon resonance of metal nanostructures. The SERS immune tags ware fabricated by functionalizing 70-nm Au nanoparticles with DTNB (i.e., 5,5′-dithiobis(2-nitrobenzoic acid)), which acted as a Raman reporter molecule, as well as the specific antibodies. These DTNB-labeled immune-AuNPs can form a sandwich structure with IL-8 antigens (infection marker) and the antibodies immobilized on the biosilica material. Our method showed an improved IL-8 detection limit in comparison to standard ELISA methods. The current detection limit for IL-8 using a conventional ELISA test is about 15.6 pg mL−1. The lower detection limit for IL-8 in blood plasma was estimated to be 6.2 pg mL−1. To the best of our knowledge, this is the first report on the recognition of IL-8 in human samples using a SERS-based method. This method clearly possesses high sensitivity to clinically relevant interleukin concentrations in body fluids. The average relative standard deviation of this method is less than 8%, which is sufficient for analytical analysis and comparable to those of classical ELISA methods. This SERS immunoassay also exhibits high biological specificity for the detection of IL-8 antigens. The established SERS immunoassay offers a valuable platform for the ultrasensitive and highly specific detection of immune biomarkers in a clinical setting for medical diagnostics. Graphical AbstractThe SERS-based immunoassay based on naturally generated photonic biosilica for the detection of interleukin 8 (IL-8) in human plasma samples Electronic supplementary material The online version of this article (10.1007/s00216-017-0566-5) contains supplementary material, which is available to authorized users.
- Published
- 2017