Revolutionizing healthcare with nanosensor technology

Abstract

Modern healthcare is constantly evolving due to the inclusion of many smart technologies. Nanotechnology, since its inception, has tremendous influence on this transformation. With an emphasis on healthcare applications, the current review explores recent advancements in nanomaterial-based biosensors. The tunability of nanomaterials provides control over the chemical, mechanical, thermal, and electrical properties, thus presents nanotechnology as a more promising solution to develop smart sensing, monitoring, and diagnostics. The synergistic effects and regulated interaction with a variety of bioanalytes spurred the advancements of nano empowered devices with high selectivity and sensitivity. With a focus on common nanomaterials e.g., metal and metal oxides, graphene and polymer-based nanomaterials, the review comprehensively discusses fundamentals of nano enabled biosensors and their classification based on methods of detection. Insight has been provided exploring the potential of various types of nanomaterials harnessed in the development of pioneering sensor designs in recent times. Along with addressing the current limitations, future prospects are discussed to redefine the landscape of nanobiosensors.

Fig. 1. Different milestones in the field of biosensors.

Fig. 2. Classification of nanomaterials used in biosensors for healthcare application.

Fig. 3. Classification of nanomaterial-based biosensors based on dimension and mechanism of signal transduction.

Fig. 4. Bottom-up and top-down methods for synthesizing NMs.

Fig. 5. (A) Schematic of a reduced graphene oxide based photoelectrochemical aptasensor and (B) sensing response and its mechanism at various concentration of the modified ITO. (C) Biosensors for detection of SARS-CoV-2 fabricated from Co-functionalized TiO₂ nanotube. (D) Two-dimensional gold nanoislands functionalized receptors in a dual-purpose biosensor for detection of SARS-CoV-2 by colorimetric and antigen-binding assay. Ab, antibody; Ag, antigen. (E) Effect of MoS₂ on the sensitivity of PAni-MoS₂ nanocomposites in detection of cauliflower mosaic virus. (F) Au@Ni–Fe embedded Prussian Blue Analogue nanocages for nonenzymatic detection of glucose. (G) Aptamer conjugated core shell NPs acting as nanoprobe for photothermal therapy of S. aureus and SERS detection. (H) Detection mechanism of microRNA-21 by Fe₃O₄/CeO₂@Au–S1 composite in a biosensor.

Fig. 6. (A) Illustration of doxorubicin-loaded glutathione-responsive nanosponge. (B) ZnO-encapsulated deoxyribozyme nanosponges with multivalent tandem aptamer sequences for facilitated delivery of deoxyribozyme cofactors and therapeutic ROS generators.

Fig. 7. (A) Glucose sensing mechanism by a transistor-based glucose sensor with immobilized glucose oxidase-based on polypyrrole nanowire and rGO. (B) biosensing schemes of cholesterol ester mediated by functionalized graphene and the corresponding cyclic voltammetric response in (a) absence and (b) presence of the analytes. (C) Fabrication of GO/Cu–MOF composite based immunosensor for the simultaneous detection of M. pneumoniae and L. pneumophila antigens. (D) electrochemical sensor chip containing Au NP conjugated specific antisense DNA for the digital sensing of SARS-CoV-2 genetic content. (E) Graphene enabled wearable sensor for monitoring several biomarkers during wound inflammation, repair and remolding stage. (F) Graphene-based 3D printed sensor: schematic of the 3D NPs printer, printed gold pillar array and its SEM images, the micro-textured surface of Au decorated with rGO nanosheets, and complete device integrated into a microfluidic cell.

Fig. 8. Schematic illustration of different paper-based assay for biosensing (A) dipsticks comprises of a test line and control line printed on nitrocellulose membrane (B) SP: sample pad, CP: conjugate pad, T: test line, C: control line, and AP: absorbent pad in a lateral flow assays (C) microfluidic device for detecting multiple analytes (left) and an origami-based 3D μPADs.

Fig. 9. (A) Loop-mediated isothermal amplification-based DNA detection by a paper-based microfluidic device attached with a foldable paper strip. The dark regions of paper strip contain hydrophobic wax whereas the unpattern regions allows direct sample flow. (B) Schematic of the recognition of SARS-CoV-2 spike antigen by angiotensin-converting enzyme 2 cellular membrane receptor using LFIA assay. (C) Fluorescent LFIA assay for detection of anti-SARV-CoV-2 IgG in human serum. (D) IgM–IgG antibody test kit for SARS-CoV-2 detection: illustration of the LFIA device and interpretation of the results obtained from the device where C: control line, G: IgG line, M: IgM line. (E) Mechanistic scheme of detection of avian influenza viruses (AIVs) using a nanoprobe-based chemiluminescent LFA. (F) Real time cortisol monitoring with the help of a nanofiber-based microfluidic chip integrated in molecular imprinted electrochemical sensor. (G) Gold nanomesh based wearable SERS sensor designed for detecting biomarkers in sweat (optical microscopy image of the gold nanomesh has been shown in inset).

Fig. 10. Key features and mechanism of action of nanosensors.

Fig. 11. Different types of nanoparticle delivery structures in recent vaccine technologies where (A) virus-like particle, (B) liposome, (C) immune stimulating complexes, (D) polymeric nanoparticle, (E) inorganic nanoparticle, (F) emulsion and (G) exosome..

Fig. 12. (A) Brain tumour study by AGuIX NPs grafted with a ligand peptide and integrated with porphyrin for dual mode sensing. (B) Hyperpolarized nanodiamonds for enhancement of MRI capabilities.

Fig. 13. Prospects of nanosensors of next generation healthcare.