Polymer Brush–GaAs Interface and Its Use as an Antibody-Compatible Platform for Biosensing

Abstract

Despite evidence showing that polymer brushes (PBs) are a powerful tool used in biosensing for minimizing nonspecific interactions, allowing for optimization of biosensing performance, and the fact that GaAs semiconductors have proven to have a remarkable potential for sensitive biomolecule detection, the combination of these two robust components has never been considered nor evaluated as a platform for biosensing applications. This work reports different methodologies to prepare and tune PBs on the GaAs interface (PB–GaAs) and their potential as useful platforms for antibody grafting, with the ultimate goal of demonstrating the innovative and attractive character of the PB–GaAs interfaces in the enhanced capture of antibodies and control of nonspecific interactions. Three different functionalization approaches were explored, one “grafting-to” and two “grafting-from,” in which atom transfer radical polymerization (ATRP) was performed, followed by their corresponding characterizations. Demonstration of the compatibility of Escherichia coli (E. coli) and Legionella pneumophila (Lp) antibodies with the PB–GaAs platform compared to the results obtained with conventional biosensing architectures developed for GaAs indicates the attractive potential for operation of a sensitive biosensor. Furthermore, these results showed that by carefully choosing the nature and preparation methodology of a PB–GaAs interface, it is possible to effectively tune the affinity of PB–GaAs-based sensors toward E. coli and Lp antibodies ultimately demonstrating the superior specificity of the developed biosensing platform.

Polymer Brushes on GaAs and GaAs/AlGaAs Nanoheterostructures: A Promising Platform for Attractive Detection of Legionella pneumophila

“…The spectra of compounds used for the synthesis of SAM-GaAs and PB-GaAs samples have been previously reported. 36 Figure 2 shows the FTIR absorbance spectra obtained for SAM-GaAs and PB-GaAs samples upon incubation for 1 h in IgG anti- Lp antibodies. As it can be seen, the absorption bands at 1149, 1175, and 1260 cm –1 correspond to C–O–C and C–O stretching, respectively.…”

“…A higher antibody surface coverage (∼4 times) was obtained for B-MUA-PEG as compared to A-MUA-PEG PBs, suggesting that dissolving PEG in DMF rather than MES buffer improved diamino-PEG solubility at the time of its incorporation, which has been previously demonstrated by the PB roughness factor. 36 A significant improvement of the number of immobilized antibodies was recorded with the use of protein A (∼1.5 to 2 times for A-MUA-PEG and B-MUA-PEG PBs, respectively, and up to 5 times in the case of MUA SAM), resulting in homogenous attachment of antibodies in a preferable orientation, which prevents undesired conformational changes and the insufficient exposure of functional domains.…”

“…In an attempt to address the detection of bacteria using a GaAs-based biosensor, the incorporation of PBs on GaAs has been previously reported, and different methodologies were investigated to prepare and tune PBs on the GaAs surface . The potential of PB-GaAs as a useful platform for antibody grafting was demonstrated by the binding of antibodies against E.…”

Microfluidics for High Pressure: Integration on GaAs Acoustic Biosensors with a Leakage-Free PDMS Based on Bonding Technology

“…There are several materials that can be used in the fabrication of acoustic wave sensors. GaAs has been shown to be very well suited for biosensing application [ 15 , 16 , 17 ]. GaAs is a microtechnical material that combines piezoelectric properties and the possibilities for devices integration and miniaturization.…”

Binding enhancements of antibody functionalized natural and synthetic fibers

“…44,45 Enhanced protein immobilization through coatings of polymer brushes or hydrogel layers involves additional chemical steps. 35,46 At the same time, strategies should be developed to use low amounts of proteins for immobilization while retaining high surface binding activity, especially for high-cost proteins (e.g., antibodies for detecting viruses like HPV, hepatitis C, and SARS-COV-2, etc. ).…”