Electrohydrodynamic‐Induced SERS Immunoassay for Extensive Multiplexed Biomarker Sensing

Abstract

Cancer diagnosis and patient monitoring require sensitive and simultaneous measurement of multiple cancer biomarkers considering that single biomarker analysis present inadequate information on the underlying biological transformations. Thus, development of sensitive and selective assays for multiple biomarker detection might improve clinical diagnosis and expedite the treatment process. Herein, a microfluidic platform for the rapid, sensitive, and parallel detection of multiple cancer-specific protein biomarkers from complex biological samples is presented. This approach utilizes alternating current electrohydrodynamic-induced surface shear forces that provide exquisite control over fluid flow thereby enhancing target-sensor interactions and minimizing non-specific binding. Further, the use of surface-enhanced Raman scattering-based spectral encoding with individual barcodes for different targets enables specific and simultaneous detection of captured protein biomarkers. Using this approach, the specific and sensitive detection of clinically relevant biomarkers including human epidermal growth factor receptor 2 (HER2); Mucin 1, cell surface associated (MUC1); epidermal growth factor receptor; and Mucin 16, cell surface associated (MUC16) at concentrations as low as 10 fg mL in patient serum is demonstrated. Successful target detection from patient samples further demonstrates the potential of this current approach for the clinical diagnosis, which envisages a clinical translation for a rapid and sensitive appraisal of clinical samples in cancer diagnostics.

A SERS microfluidic platform for targeting multiple soluble immune checkpoints

“…The SERS nanotags were prepared by the same method as described by our previous studies(Kamil Reza et al 2016). The gold nanoparticles were synthesized by citrate reduction of HAuCl4 as reported in literature.…”

“…To address this limitation, we have recently developed a SERS-microfluidic platform which utilizes alternating current electrohydrodynamic (ac-EHD) fluid flow thus avoiding the use of any external pump. This ac-EHD induced fluid flow generates a nanoscale shear force at the double layer of the sensing electrodes which significantly increases the antibody-target binding and at the same time shears off the non-specifically bound molecules from the sensor surface (Kamil Reza et al 2016;Wang et al 2015). Despite this advantages, this method utilized biotin-streptavidin chemistry followed by immune-affinity approach using monoclonal antibody which limits its application in clinical settings.…”

SERS Nanotags and Their Applications in Biosensing and Bioimaging

“…This study demonstrated that the proposed platform was highly sensitive (10 fg/mL) and had great potential to detect protein biomarkers in patient samples. This platform was further developed to simultaneously detect multiple cancer protein biomarkers from clinical samples by using 4 different SERS nanotags [96]. They constructed a microfluidic device containing five individual microchannels with each channel comprehending an array of asymmetric electrode pairs (Fig.…”

“…Cited from Ref. [126], [95], [96] and [99] immunoassay method using electrohydrodynamic (ac-EHD) force to markedly reduce the assay time and nonspecific binding for breast cancer biomarkers detection (Fig. 3B) [95].…”

Engineering surface-enhanced Raman scattering strategies for liquid biopsy analyses: a step towards precision medicine in cancer management

“…154 There is also ample evidence suggesting that a panel of protein biomarkers provide more information than a single one for clinical diagnosis, 155,156 [163][164][165][166][167] and (iv) microfluidic immunoassays. [168][169][170][171] The captured proteins are then detected based on either the "fingerprint" information of target proteins 172,173 or the characteristic spectra of Raman reporters conjugated to plasmonic nanomaterials. 41,61,[157][158][159][160][161][162][163][164][165][166][168][169][170][171][174][175][176][177][178] Although both SERS read-out methods can provide sensitive and specific detection of circulating target proteins, nanotag-based SERS immunoassays are more commonly used due to the availability of direct multiplex readouts based on unique spectral signals and strong signals provided by the Raman reporters with large SERS cross sections.…”