Parallel profiling of cancer cells and proteins using a graphene oxide functionalized ac-EHD SERS immunoassay

Abstract

Circulating biomarkers have emerged as promising non-invasive, real-time surrogates for cancer diagnosis, prognosis and monitoring of the therapeutic response. Current bio-sensing techniques mostly involve detection of either circulating cells or proteins which are inadequate in unfolding complex pathologic transformations. Herein, we report parallel detection of cellular and molecular markers (protein) for cancer using a multiplex platform featuring (i) graphene oxide (GO) functionalization that increases the active surface area and more importantly reduces the functionalization steps for rapid detection, (ii) alternating-current electrohydrodynamic (ac-EHD) fluid flow that provides delicate micro-mixing to enhance target-sensor interactions thereby minimizing non-specific binding and (iii) surface enhanced Raman scattering (SERS) for multiplex detection. We find that our platform possesses high sensitivity for detecting both proteins and cells. More importantly, this platform not only detects the cancer cells but also can simultaneously monitor the heterogeneous expression of cell surface proteins which could be clinically useful to determine effective patient therapy. We demonstrate the specific and sensitive detection of breast cancer cells from a mixture of non-target cells and report the heterogeneous expression of human epidermal growth factor receptor 2 (HER2) proteins on the individual cancer cell surface. Concurrently, we detect as low as 100 fg mL HER2 and Mucin 16 proteins spiked in blood serum.

Cancer Diagnosis through SERS and Other Related Techniques

“…Reza et al developed a graphene oxide (GO) biochip, which combines alternating-current electrohydrodynamic (ac-EHD) fluid flow to simultaneously isolate CTCs and soluble protein biomarkers from biological samples, to then characterize cell surface protein biomarkers by SERS. (Figure 5A) [59]. In this manner, they profiled HER2 protein expression levels on breast cancer cell surfaces and meanwhile identified two soluble protein biomarkers (HER2 and MUC16) from simulated biological fluid.…”

The Growing Impact of Micro/Nanomaterial‐Based Systems in Precision Oncology: Translating “Multiomics” Technologies

“…More recently, Reza et al have modified the strategy by incorporating the electric fieldinduced fluid flow technique into a graphene oxide-based SERS immunoassay for parallel detection of CTCs and circulating proteins. [143] However, it is worth noting that both strategies were preliminary demonstrated using artificially contaminated samples for interspecies biomarker detection and yet to be further subjected to real clinical sample testing.…”

Application of Functionalized Graphene Oxide Based Biosensors for Health Monitoring: Simple Graphene Derivatives to 3D Printed Platforms

“…Furthermore, GO has a high surface area to volume ratio that provides abundant active sites for direct coupling with the antibody resulting in improved system performance. Moreover, GO-based immunoassay has successfully demonstrated a much wider dynamic range and was found to be more sensitive than the same immunoassay using biotin-streptavidin functionalization [14].…”

“…To fabricate optical sensors, GO can be processed in colloidal suspension and it is easily complexed with biomolecules to produce highly efficient long-range photoluminescence signals [10]. The properties of graphene and its derivatives have been explored for developing label-free optical sensors such as optical fiber-based sensors, surface plasmon resonance (SPR) sensing, and surface-enhanced Raman scattering for bioimaging, antibacterial activity, and drug delivery system [13,14]. Furthermore, GO has a high surface area to volume ratio that provides abundant active sites for direct coupling with the antibody resulting in improved system performance.…”

“…Currently, integration of graphene with optofluidic and electrochemical microfluidic chips is of great interest in biomarker sensing owing to offering multiplex sensing with high sensitivity and militarization. Trau et al developed a microfluidic platform that uses GO and gold-based biochips for sensitive cell and protein analysis in human serum samples [14]. GO containing negatively charged oxygenated functional groups at physiological pH, and the hexagonal aromatic graphene structure, promoted hydrogen bonding and electrostatic, hydrophobic van der Waals, and π-π interactions allowing it to interact with protein analytes [16].…”