Graphene Enabled Low‐Noise Surface Chemistry for Multiplexed Sepsis Biomarker Detection in Whole Blood

Abstract

Affinity‐based electrochemical (EC) sensors offer a potentially valuable approach for point‐of‐care (POC) diagnostics applications, and for the detection of diseases, such as sepsis, that require simultaneous detection of multiple biomarkers, but their development has been hampered due to biological fouling and EC noise. Here, an EC sensor platform that enables detection of multiple sepsis biomarkers simultaneously by incorporating a nanocomposite coating composed of crosslinked bovine serum albumin containing a network of reduced graphene oxide nanoparticles that prevents biofouling while maintaining electroconductivity is described. Using nanocomposite coated planar gold electrodes, a sensitive procalcitonin (PCT) sensor is constructed and validated in undiluted serum, which produced an excellent correlation with a conventional ELISA (adjusted r2 = 0.95) using clinical samples. A single multiplexed platform containing sensors for three different sepsis biomarkers—PCT, C‐reactive protein, and pathogen‐associated molecular patterns—is also developed, which exhibits specific responses within the clinically significant range without any cross‐reactivity. This platform enables sensitive simultaneous EC detection of multiple analytes in human whole blood, and it can be applied to detect any target analyte with an appropriate antibody pair. Thus, this nanocomposite‐enabled EC sensor platform may offer a potentially valuable tool for development of a wide range of clinical POC diagnostics.

Rapid antifouling nanocomposite coating enables highly sensitive multiplexed electrochemical detection of myocardial infarction and concussion markers

“…Incorporating terminal amine groups in rGOx augments their interaction with polymer matrices and their distribution by altering their solubility and agglomeration, in addition to enhancing the physical, mechanical, thermal, and electrical stability of the composite via covalent linking of the amines by GA pyridine polymers. 16, 17 Indeed, when we compared the effects of amine-functionalized rGOx we used previously versus pentaamine-functionalized rGOx (prGOx), we found that the prGOx maintained a higher current density and lower peak-to-peak distance when measured immediately after coating or after incubating in 1% BSA for 1h or 1 day ( Fig. 1b ).…”

“…To develop an efficient process flow for mass manufacturing, a nanocomposite coating method was developed using on-chip heating to facilitate rapid deposition of our previously described BSA/rGOx composite. 17 Clean gold electrodes were heated at 85 0 C with the nanocomposite material for 30 sec to 5 min, followed by washing in PBS immediately or after cooling down for 10 min. This ultra-rapid cross-linking mechanism results in creation of porous three dimensional (3D) molecular networks, and we were able to detect this reaction by measuring increase in absorbance at 265-270 nm (Supplementary Fig.…”

“…We previously described a highly effective anti-fouling nanocomposite coating composed of denatured bovine serum albumin (BSA) cross-linked to gold nanomaterials or reduced graphene nanoparticles (rGOx) using glutaraldehyde (GA). 12, 17 While this method was simple and greatly suppressed signal noise due to biofouling, it took 24 hours to prepare these surfaces. Here, we report an alternative version of this nanocomposite coating that is composed of BSA cross-linked to pentaamine graphene flakes that can be coated on EC sensors using localized heating in the unprecedented time of less than one minute, which allows for outstanding signal transduction between the gold electrode and the nanocomposite surface.…”

Electrochemical Immunosensors for Quantification of Procalcitonin: Progress and Prospects

“…Several recent reports on multiplexed sensors with PCT as one of the analytes are available in literature [48]. A lab-on-a-chip immunosensor array was reported for simultaneous detection of the pro-inflammatory markers PCT, interleukin-6 (IL-6) and C-reactive protein (CRP) using a cyclooctene (TCO)-tetrazine (Tz)-horse radish peroxidase (HRP) assembly [49]. The ratio of TCO-HRP and Tz-HRP was optimized to achieve adequate chemiluminescent response for the different markers that are present in varying levels in blood.…”

Graphene FET Sensors for Alzheimer’s Disease Protein Biomarker Clusterin Detection

“…Here we demonstrate the sensitivity, repeatability and specificity of the GFET biosensors for the detection of pure proteins. The next stage of the study will be to investigate the sensor response using real patient samples (such as serum, plasma, or blood), stability and storage of the sensors (Teixeira et al, 2014;Leva-Bueno et al, 2020;Zupančič et al, 2021). Thus, GFET biosensors offer a unique route towards the development of vitally needed diagnostic platform for AD.…”