Photoswitchable Machine-Engineered Plasmonic Nanosystem with High Optical Response for Ultrasensitive Detection of microRNAs and Proteins Adaptively

Abstract

Modulating optoelectronic properties of inorganic nanostructures tethered with light-responsive molecular switches by their conformational change in the solid state is fundamentally important for advanced nanoscale-device fabrication, specifically in biosensing applications. Herein, we present an entirely new solid-state design approach employing the light-induced reversible conformational change of spiropyran (SP)-merocyanine (MC) covalently attached to gold triangular nanoprisms (Au TNPs) via alkylthiolate self-assembled monolayers to produce a large localized surface plasmon resonance response (∼24 nm). This shift is consistent with the increase in thickness of the local dielectric shell-surrounded TNPs and perhaps short-range dipole−dipole (permanent and induced) interactions between TNPs and the zwitterionic MC form. Water contact angle measurement and Raman spectroscopy characterization unequivocally prove the formation of a stable TNP-MC structural motif. Utilizing this form, we fabricated the first adaptable nanoplasmonic biosensor, which uses an identical structural motif for ultrasensitive, highly specific, and programmable detection of microRNAs and proteins at attomolar concentrations in standard human plasma and urine samples, and at femtomolar concentrations from bladder cancer patient plasma (n = 10) and urine (n = 10), respectively. Most importantly, the TNP-MC structural motif displays a strong binding affinity with receptor molecules (i.e., single-stranded DNA and antibody) producing a highly stable biosensor. Taken together, the TNP-MC structural motif represents a multifunctional super biosensor with the potential to expand clinical diagnostics through simplifying biosensor design and providing highly accurate disease diagnosis.

Selective Detection and Ultrasensitive Quantification of SARS-CoV-2 IgG Antibodies in Clinical Plasma Samples Using Epitope-Modified Nanoplasmonic Biosensing Platforms

“…To overcome these drawbacks, several plasmonic nanostructured-based (“nanoplasmonic”), solid-state serology assays have been developed for COVID-19 antibody detection. ,,,− Nanoplasmonic assays utilize the unique localized surface plasmon resonance (LSPR) property of noble metal nanostructures that originates due to collective oscillation of free electrons upon light irradiation. , Furthermore, with an appropriate choice of nanostructures, along with the suitable surface chemistry anchoring receptor molecules, highly sensitive and specific nanoplasmonic biosensors can be fabricated for protein assays in human biofluids. − In the context of COVID-19 serology antibody assays, current plasmonic-based antibody assays lack specificity. , Moreover, these assays use an anti-human antibody (anti-IgG, anti-IgM, and anti-IgA) as receptor molecules in the biosensor construct to detect SARS-CoV-2 antibodies (IgG, IgM, and IgA). ,,− However, these anti-human antibodies (anti-IgG, anti-IgM, and anti-IgA) are known to be abundant in blood and may compete with target SARS-CoV-2 antibodies for binding with anti-human antibody receptors, leading to non-SARS-CoV-2 antibody specific receptors. ,,, In order to develop a highly specific serology antibody assay for COVID-19, one must select a SARS-CoV-2 antibody specific receptor.…”

Gabapentin Disrupts Binding of Perlecan to the α2δ1 Voltage Sensitive Calcium Channel Subunit and Impairs Skeletal Mechanosensation

“…Au TNPs were chemically synthesized according to published procedures [ 46 , 47 , 48 ]. Briefly, 10.4 mg (0.05 mM) of chloro(triethyphosphine)gold(I) [Et 3 Pau(I)Cl] were dissolved in N 2 purged acetonitrile (20 mL) and stirred at RT for 5–10 min.…”

Gold Triangular Nanoprisms: Anisotropic Plasmonic Materials with Unique Structures and Properties

“…The reversible conformational change of spiropyran under the induction of light was transformed into a merocyanine, resulting in a large LSPR response (Figure 15C). [104] The sensor could be employed to detect miR‐10b, −145 and nuclear mitotic apparatus protein‐1 in body fluids of cancer patients sensitively. The detection of different targets on the same sensor was achieved by exchanging with programmable ssDNA or protein receptor molecules adsorbed in the form of merocyanine activated by visible light.…”