Reviewing advances in nanophotonic biosensors

Abstract

Biosensing, a promising branch of exploiting nanophotonic devices, enables meticulous detection of subwavelength light, which helps to analyze and manipulate light-matter interaction. The improved sensitivity of recent high-quality nanophotonic biosensors has enabled enhanced bioanalytical precision in detection. Considering the potential of nanophotonics in biosensing, this article summarizes recent advances in fabricating nanophotonic and optical biosensors, focusing on their sensing function and capacity. We typically classify these types of biosensors into five categories: phase-driven, resonant dielectric nanostructures, plasmonic nanostructures, surface-enhanced spectroscopies, and evanescent-field, and review the importance of enhancing sensor performance and efficacy by addressing some major concerns in nanophotonic biosensing, such as overcoming the difficulties in controlling biological specimens and lowering their costs for ease of access. We also address the possibility of updating these technologies for immediate implementation and their impact on enhancing safety and health.

Keywords: biomolecules; challenges; nanophotonic biosensors; phase-driven sensors; surface plasmon resonance.

FIGURE 1

(A) Diagrammatic working representation of a standard nanophotonic biosensor detecting viruses (Bannur et al., 2022). (B) Important parts of a biosensor, while the analytes may be an antibody, protein, or enzyme (Singh et al., 2023).

FIGURE 2

Diagrammatic view of biosensing mechanism. Bio-receptors bind to the surface of the target analyte. Any change in the signal is detected by the transducers, and then the transducers translate it to a quantifiable outcome due to the resemblance between the target analyte and the receptor. The signal can be converted into any other form with the help of light-based, thermal, or electrochemical techniques. The output signal is processed further or transported to the target tool with the help of chip-based or traditional electronics. Recent biosensors have built-in data bank models of communication that help transmit digital data to smart devices. To examine the health of individuals, this enables the derived signals to be portrayed on any device (Polat et al., 2022).

FIGURE 3

Nanostructures that respond to the incident light field are commonly seen in nanophotonic biosensors. The augmented evanescent field is used to detect changes in refractive index at the interface caused by biorecognition events such as interactions between antibodies and antigens (Soler et al., 2020).

FIGURE 4

(A) Schematic of the evanescent wave-based biosensor, and (B) Full-wave electromagnetic analysis with the help of a 2D model (Hwang, 2021).

FIGURE 5

An outline highlighting the important variables such as biochemical, computational, and physical variables that affect the capability of nanophotonic biosensors to visualize the data (Yesilkoy, 2019).

FIGURE 6

Biosensing based on SPR and LSPR. (A) SPR setup (Anand et al., 2022), (B) LSPR setup (Miranda et al., 2021), (C) LSPR from metal NP, (D) Comparison of SPR and LSPR, (E) Plasmon resonance criterion (Xiao et al., 2023) and (F) Various structures based on plasmonics and metamaterials used to probe biosensing (Hassan et al., 2021).

FIGURE 7

(A) SPR biosensing mechanism (Hassan et al., 2021). (B) Schematic of graphene-based biosensing setup, and (C) SPR signal (Écija-Arenas et al., 2021). (D) Schematic of MoS₂-based hybrid materials for biosensing, (E) Change in reflectance as a function of angle at varying concentrations, and (F) Change angle as a function of varying concentrations (Nie et al., 2017).

FIGURE 8

(A) Schematics of the optical setup of the phase-sensitive detection apparatus. The back focal plane of a 5-times objective gets a focused beam from an 855 nm laser diode. This setup confirms that the guided-mode resonance is stimulated by collimated light. In the grating grooves, the incoming light’s polarization is positioned at a 45° angle, making the TE and TM modes equally excitable. The sensor’s resonantly reflected light comprises phase information and the effective RI of the orthogonally polarized guided modes. With the help of the Wollaston prism, an angle of 1° is established within the two modes with an orientation of about 45°. The two beams bisect in the camera plane, building a highly diverse interferogram, and (B) At an analyzer orientation of around 45°, the two divergent beams meet in the camera plane, resulting in a high-contrast interferogram (Barth et al., 2020).

FIGURE 9

SERS-based biosensing (A) Incorporating the metasurface of Si-dimer nanoantenna, (B) Nile red emission spectrum as a function of wavelength. The inset shows temperature-dependent spectra and (C) Plots of temperature vs. laser intensity for Au and Si (Caldarola et al., 2015) (D) Schematic setup of Si₃N₄ exhibiting BIC mode, (E) Raman emission spectra of the CV in and out PhCM, and (F) Transmission spectra depicting dispersion bands (Romano et al., 2018b).

FIGURE 10

(A) Schematic setup for the phase detection of analytes in situ SEIRA based on reflection mode. (B) The lipid membrane has been monitored with the help of molecular-specific in situ SEIRA over the Au antenna coated with SiO₂, where the bursting of lipid vesicles occurs with the help of cytolytic peptide melittin injection, resulting in the formation of a lipid bilayer membrane. (C) Buffer containing Au nano-antenna, and the electric-field outcome. The signal dependence of SEIRA has been displayed after contrasting it with computer calculations (shown as dots) and absorbance data. (D) Nano FTIR absorption and setup of a graphene liquid cell depicting the mechanism of trapping biomolecules in the water layer (Oh et al., 2021).

FIGURE 11

(A) SERS improvement is based on coverage. At 785 nm, the incident light is shown as solid lines. The dotted lines represent incident light at 633 nm (blue) and 900 nm (red) for nanospheres and nanostars, respectively, and (B) This schematic depicts the monolayers’ increased coverage (Solís et al., 2017). (C) The manufacturing scheme for antibody-conjugated Fe₃O₄@Au SERS nanotags, (D) SAA and Raman intensity calibration curves, and (E) Raman intensity and CRP calibration curve (Liu et al., 2020).

FIGURE 12

(A) A diagrammatic depiction of phase behavior and direct phase interrogation via polarization beam shearing, inspired by an interferometric dielectric platform (Barth et al., 2020) and a phase-sensitive plasmonic biosensor (Yesilkoy et al., 2018), and (B) Schematic represented by Zhu et al. (Zhu et al., 2024). This photograph is adapted from (Barth and Lee, 2024).

FIGURE 13

An illustrative overview of challenges and perspectives of nanophotonic biosensors.

FIGURE 14

(A) Planar and vertical systems for integrating the biosensors, including several different layers and elements, and (B) Illustration of the nanophotonic components along with the most commonly used biofunctionalization surface methods (Altug et al., 2022).