Intuitive Label-Free SERS Detection of Bacteria Using Aptamer-Based in Situ Silver Nanoparticles Synthesis

Abstract

The characteristic of an ideal bacteria-detection method should have high sensitivity and specificity, be easy to operate, and not have a time-consuming culture process. In this study, we report a new bacteria-detection strategy that can recognize bacteria quickly and directly by surface-enhanced Raman scattering (SERS) with the formation of well-defined bacteria-aptamer@AgNPs. SERS signals generated by bacteria-aptamer@AgNPs exhibited a linear dependence on bacteria (R = 0.9671) concentration ranging from 10 to 10 cfu/mL. The detection limit is sensitive down to 1.5 cfu/mL. Meanwhile, the bacteria SERS signal was dramatically enhanced by its specifically recognized aptamer, and the bacteria could be identified directly and visually through the SERS spectrum. This strategy eliminates the puzzling data analysis of previous studies and offers significant advantages over existing approaches, getting a critical step toward the creation of SERS-based biochips for rapid in situ bacteria detection in mixture samples.

Marine Toxins Detection by Biosensors Based on Aptamers

“…This article reviews the detection of marine toxins by aptamer-based biosensors, as well as the selection approach for the systematic evolution of ligands by exponential enrichment (SELEX), the aptamer sequences. Moreover, the newest aptasensors and the future prospective are also discussed, which would provide thereotical basis for the future development of marine toxins detection by aptasensors.Key Contribution: This article reviews systematically the toxicity of marine toxins, the development of aptarmer-based biosensors, and progress in the marine toxin detection by aptasensors.Toxins 2020, 12, 1 2 of 22 selection technology and biosensor fabrication technology offer a new solution for the detection of marine toxins with high efficiency and sensitivity [13][14][15][16][17].Marine toxins are a class of small molecular compounds mainly produced by red tide algae. In recent years, with the aggravation of environmental pollution, human deaths due to accidental ingestion of toxic shellfish are also often reported [18][19][20][21].…”

“…Toxins 2020, 12, 1 2 of 22 selection technology and biosensor fabrication technology offer a new solution for the detection of marine toxins with high efficiency and sensitivity [13][14][15][16][17].…”

Fabrication and Applications of 3D Nanoarchitectures for Advanced Electrocatalysts and Sensors

“…In particular, aptamers have demonstrated the ability to capture various chemicals, ions, and even complex biomolecules with high selectivity. [277][278][279] Aptamers are a single strand of DNA or RNA which wraps around the target analyte and holds the analyte in place through intermolecular interactions. [280] They can position analytes within a distance that is short enough for the generated Raman signal to be amplified by the SERS substrate.…”

Current and Emerging Technologies for Rapid Detection of Pathogens

“…With this regard, a lot of label-free methods have been developed for the detection of pathogens. For example, Gao's group [78] successfully achieved intuitive label-free SERS detection of bacteria using aptamerbased in situ Ag NP synthesis. The biosensor as prepared can recognize bacteria quickly and directly by SERS with the formation of well-defined bacteria-aptamer@Ag NPs.…”