Ultrasensitive SERS immunoassay based on diatom biosilica for detection of interleukins in blood plasma.
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 Abstract The SERS-based immunoassay based on naturally generated photonic biosilica for the detection of interleukin 8 (IL-8) in human plasma samples.
['Kamińska|Agnieszka|A|', 'Sprynskyy|Myroslav|M|', 'Winkler|Katarzyna|K|', 'Szymborski|Tomasz|T|']
D015374:Biosensing Techniques D017377:Diatoms D006046:Gold D006801:Humans D007118:Immunoassay D016209:Interleukin-8 D057230:Limit of Detection D053768:Metal Nanoparticles D015203:Reproducibility of Results D012822:Silicon Dioxide D013059:Spectrum Analysis, Raman
Immunoassay Diatom biosilica Interleukin 8 Surface-enhanced Raman spectroscopy (SERS)