SERS Sensors Based on Aptamer-Gated Mesoporous Silica Nanoparticles for Quantitative Detection of Staphylococcus aureus with Signal Molecular Release

Abstract

This work describes a simple and novel biosensor for the quantitative determination of Staphylococcus aureus (S. aureus) based on target-induced release of signal molecules from aptamer-gated aminated mesoporous silica nanoparticles (MSNs) coupled with surface-enhanced Raman scattering (SERS) technology. MSNs were synthesized and then modified with amino groups by (3-aminopropyl) triethoxysilane to make them positively charged. Next, signal molecules (4-aminothiophenol, 4-ATP) were loaded into the pores of MSNs. Then, negatively charged aptamers of S. aureus were assembled on the surface of MSNs through electrostatic interactions. Upon the addition of S. aureus, the assembled aptamers were specifically bound to the bacteria. Consequently, the “gates” were opened, resulting in the release of 4-ATP from the pores of MSNs. The released molecules were measured by a Raman spectrometer, and the intensity of 4-ATP at 1071 cm–1 was linearly related to the S. aureus concentration. A silver nanoflower silica core–shell structure (Ag NFs@SiO2) was prepared and it served as a SERS substrate. Under optimized experimental conditions, a good linear relationship (y = 2107.93 + 1536.30x, R 2 = 0.9956) in the range from 4.7 × 10 to 4.7 × 108 cfu/mL was observed with a limit of detection of 17 cfu/mL. The method was successfully applied for the analysis of S. aureus in fish samples and the recovery rate was 91.3–109%.

Rapid Detection of Staphylococcus aureus Using Paper-Derived Electrochemical Biosensors

“…While a number of technologies have already been presented for the detection of S. aureus, − including sensors based on aptamers, − immunoglobulins, , proteases, or PCR amplification, the proposed sensor could not only avoid the use of biorecognition elements but also sample pretreatments, as it could be directly applied to the skin.…”

Recent Advances in Aptasensors For Rapid and Sensitive Detection of Staphylococcus Aureus

“…Silica is an ideal shell material because it has no absorbance in the visible wavelength band and is somewhat hydrophilic ( Li et al, 2017a ). Zhu et al proposed a SERS sensor for the detection of S. aureus , which based on S. aureus can induce release of the Raman dye 4-aminothiophenol (4-ATP) from mesoporous silica nanoparticles (MSNs) by binding to the gating aptamer ( Figure 5B ) ( Zhu et al, 2021b ). The SERS sensor is low-cost, fast, high sensitivity (17 CFU/ml), wide linearity (4.7 × 10 CFU/ml-4.7 × 10 8 CFU/ml), and is more reliable for detection of foodborne pathogens ( Zhu et al, 2021b ).…”

“…Zhu et al proposed a SERS sensor for the detection of S. aureus , which based on S. aureus can induce release of the Raman dye 4-aminothiophenol (4-ATP) from mesoporous silica nanoparticles (MSNs) by binding to the gating aptamer ( Figure 5B ) ( Zhu et al, 2021b ). The SERS sensor is low-cost, fast, high sensitivity (17 CFU/ml), wide linearity (4.7 × 10 CFU/ml-4.7 × 10 8 CFU/ml), and is more reliable for detection of foodborne pathogens ( Zhu et al, 2021b ). The nanodimer and nanotrimer are also widely used as SERS substrates and show a greater increase in SERS signal compared to monodisperse particles ( Ma et al, 2021 ).…”

“…(B) Schematic illustration of S. aureus detection based on the target-responsive release of 4-ATP molecules from aptamer-gated MSNs. Reproduced with permission ( Zhu et al, 2021b ). (C) Schematic illustration of the CRET biosensor for the detection of S. aureus based on Co 2+ /ABEI-AuNFs and WS 2 nanosheet.…”

Aptamer-Gated Mesoporous Silica Nanoparticles for N Protein Triggered Release of Remdesivir and Treatment of Novel Coronavirus (2019-nCoV)

“…In this study, N protein aptamer-gated mesoporous silica nanoparticles (MSNs) for targeted delivery of RDV is proposed. MSNs are considered to have unique advantages of a porous structure and nontoxicity that enable them to load and deliver drugs in vivo [ 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ]. N protein, as a major structural protein of coronavirus, plays an important role in packaging the RNA genome into helical ribonucleoproteins, modulating host cell metabolism, and regulating viral RNA synthesis during replication and transcription [ 41 , 42 ].…”