Antifouling (Bio)materials for Electrochemical (Bio)sensing

Abstract

(Bio)fouling processes arising from nonspecific adsorption of biological materials (mainly proteins but also cells and oligonucleotides), reaction products of neurotransmitters oxidation, and precipitation/polymerization of phenolic compounds, have detrimental effects on reliable electrochemical (bio)sensing of relevant analytes and markers either directly or after prolonged incubation in rich-proteins samples or at extreme pH values. Therefore, the design of antifouling (bio)sensing interfaces capable to minimize these undesired processes is a substantial outstanding challenge in electrochemical biosensing. For this purpose, efficient antifouling strategies involving the use of carbon materials, metallic nanoparticles, catalytic redox couples, nanoporous electrodes, electrochemical activation, and (bio)materials have been proposed so far. In this article, biomaterial-based strategies involving polymers, hydrogels, peptides, and thiolated self-assembled monolayers are reviewed and critically discussed. The reported strategies have been shown to be successful to overcome (bio)fouling in a diverse range of relevant practical applications. We highlight recent examples for the reliable sensing of particularly fouling analytes and direct/continuous operation in complex biofluids or harsh environments. Opportunities, unmet challenges, and future prospects in this field are also pointed out.

Two-in-one strategy: a remineralizing and anti-adhesive coating against demineralized enamel

“…It is considered the "gold standard" of antibiofouling polymers and has been widely used in biomedical systems. 17,18 When tethered to surfaces, PEG acts as a brush-like barrier 19 to inhibit nonspecific adsorption of microorganisms, such as PEGylated phasetransitioned lysozyme nanofilm for resisting the attachment of oral bacteria, 20 and (PEG)-based copolymer reducing the accumulation of cariogenic bacteria on dental surfaces. 21 In the present study, we aimed to construct a bifunctional material by combining the anti-adhesive property of PEG and the remineralization property of PASP and applied it to the repair of demineralized enamel for the first time.…”

Advanced Soft Materials, Sensor Integrations, and Applications of Wearable Flexible Hybrid Electronics in Healthcare, Energy, and Environment

“…[32] Such antifouling layers can prevent the degradation of the sensing materials in high-humidity and salt environments, thereby retaining initial degree of sensing capabilities. [229][230][231] As an additional consideration, transdermal drug delivery systems, equipped with therapeutic tips or layers under the WFHE, highly require the selective permeability for vital chemicals to the outer layer of skin (stratum corneum). [25,[232][233][234]…”

“…In this case, the membrane has a certain degree of hydrophobicity to change interfacial energy, [229] enable a better orientation of immobilized antibodies, [246] or prevent the formation of a hydration layer as well as the adhesion of bacteria. [231,247]…”

Beyond Sensitive and Selective Electrochemical Biosensors: Towards Continuous, Real-Time, Antibiofouling and Calibration-Free Devices

“…The impressive opportunities and capabilities that electrochemical biosensors offer for the monitoring of a wide variety of molecules in situ in complex or biological fluids over a prolonged period of time are limited by the gradual passivation of the (bio)sensing surface due to the nonspecific accumulation of macromolecules present in such matrices. These biofouling issues reduce the direct contact of the target analyte with the electrode surface, hampering the electron transfer, and may severely affect the sensitivity, reproducibility, stability, and overall reliability of the resulting (bio)sensors [ 29 ]. Therefore, the development of biosensors with antibiofouling properties able to keep their performance after direct/prolonged incubation in complex and protein-rich media has encouraged the utmost interest.…”

“…Among all the strategies currently available to develop antibiofouling surfaces, the modification of electrode substrates with different biomaterials, including monolayers, transient polymeric coatings, or multifunctional peptides, is particularly attractive and promising. These strategies have been recently reviewed [ 29 ], and, therefore, this section discusses only remarkable features of a limited number of selected methods.…”