Label-Free Protein Detection by Micro-Acoustic Biosensor Coupled with Electrical Field Sorting. Theoretical Study in Urine Models

Abstract

Diagnostic devices for point-of-care (POC) urine analysis (urinalysis) based on microfluidic technology have been actively developing for several decades as an alternative to laboratory based biochemical assays. Urine proteins (albumin, immunoglobulins, uromodulin, haemoglobin etc.) are important biomarkers of various pathological conditions and should be selectively detected by urinalysis sensors. The challenge is a determination of different oligomeric forms of the same protein, e.g., uromodulin, which have similar bio-chemical affinity but different physical properties. For the selective detection of different types of proteins, we propose to use a shear bulk acoustic resonator sensor with an additional electrode on the upper part of the bioliquid-filled channel for protein electric field manipulation. It causes modulation of the protein concentration over time in the near-surface region of the acoustic sensor, that allows to distinguish proteins based on their differences in diffusion coefficients (or sizes) and zeta-potentials. Moreover, in order to improve the sensitivity to density, we propose to use structured sensor interface. A numerical study of this approach for the detection of proteins was carried out using the example of albumin, immunoglobulin, and oligomeric forms of uromodulin in model urine solutions. In this contribution we prove the proposed concept with numerical studies for the detection of albumin, immunoglobulin, and oligomeric forms of uromodulin in urine models.

Development of a textile based protein sensor for monitoring the healing progress of a wound

“…The use of BSA as a protein source specifically when testing electro-chemical sensors has been previously reported by others 44 because the concentration can be easily standardized and altered precisely to evaluate the detection range. Most importantly, the properties of BSA are very similar to human serum albumin with respect to other proteins as discussed in a recent paper 38 .…”

“…While pH and temperature have been used as parameters in assessing wound status 33 – 35 , detecting protein concentrations helps to identify wound healing stages 36 as it is less likely to be affected by the active external environment surrounding the exudate. Albumin was the protein determined in this research work, which has been modelled and measured previously 37 , 38 as it is the most abundant protein in blood plasma (it represents of total protein) 39 , previous research has shown a relation between the wellness of a person and the albumin concentration 40 , establishing albumin concentration as a good marker of protein concentrations in wounds. Albumin concentrations in wounds have been used as indicator of wound severity conditions, for which a concentration of mg/mL is in inflamed wounds 41 .…”

Development of a Textile Based Protein Sensor for Monitoring the Healing Progress of a Wound

“…The use of BSA as a protein source specifically when testing electro-chemical sensors has been previously reported by others 48 because the concentration can be easily standardized and altered precisely to evaluate the detection range. Most importantly, the properties of BSA are very similar to human serum albumin with respect to other proteins as discussed in a recent paper 42 .…”

“…While pH and temperature have been used as parameters in assessing wound status 38,39 , detecting protein concentrations helps to identify wound healing stages 40 as it is less likely to be affected by the active external environment surrounding the exudate. Albumin was the protein determined in this research work, which has been modelled and measured previously 41,42 as it is the most abundant protein in blood plasma (it represents 50% of total protein) 43 , previous research has shown a relation between the wellness of a person and the albumin concentration 44 , establishing albumin concentration as a good marker of protein concentrations in wounds. Albumin concentrations in wounds have been used as indicative of wound severity conditions, for which a concentration of > 15 mg/ml is considered to be present in inflamed wounds 45 .…”

Effects of Buffer Concentration on the Sensitivity of Silicon Nanobelt Field-Effect Transistor Sensors

“…Chemical and biological sensors have attracted much attention because of their wide applicability in daily life [ 1 , 2 , 3 , 4 ]. The demand for reliable, ultrasensitive, and portable sensors is increasing in fields such as disease diagnostics, human health, and environmental monitoring [ 5 , 6 ].…”