scholarly journals Optical Biosensors for Label-Free Detection of Small Molecules

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4126 ◽  
Author(s):  
Riikka Peltomaa ◽  
Bettina Glahn-Martínez ◽  
Elena Benito-Peña ◽  
María Moreno-Bondi
Keyword(s):  
Small Molecules ◽  
High Sensitivity ◽  
Surface Enhanced Raman Spectroscopy ◽  
Optical Biosensors ◽  
Label Free ◽  
Fiber Sensors ◽  
Label Free Detection ◽  
Surface Enhanced Raman ◽  
Resonance Surface ◽  
Small Molecule Detection

Label-free optical biosensors are an intriguing option for the analyses of many analytes, as they offer several advantages such as high sensitivity, direct and real-time measurement in addition to multiplexing capabilities. However, development of label-free optical biosensors for small molecules can be challenging as most of them are not naturally chromogenic or fluorescent, and in some cases, the sensor response is related to the size of the analyte. To overcome some of the limitations associated with the analysis of biologically, pharmacologically, or environmentally relevant compounds of low molecular weight, recent advances in the field have improved the detection of these analytes using outstanding methodology, instrumentation, recognition elements, or immobilization strategies. In this review, we aim to introduce some of the latest developments in the field of label-free optical biosensors with the focus on applications with novel innovations to overcome the challenges related to small molecule detection. Optical label-free methods with different transduction schemes, including evanescent wave and optical fiber sensors, surface plasmon resonance, surface-enhanced Raman spectroscopy, and interferometry, using various biorecognition elements, such as antibodies, aptamers, enzymes, and bioinspired molecularly imprinted polymers, are reviewed.

scholarly journals A Simple Displacement Aptamer Assay on Resistive Pulse Sensor for Small Molecule Detection

2020 ◽  
Author(s):  
Rhushabh Maugi ◽  
bernadette gamble ◽  
david bunka ◽  
Mark Platt
Keyword(s):  
Small Molecules ◽  
Small Molecule ◽  
Label Free ◽  
Resistive Pulse ◽  
Pulse Sensor ◽  
Label Free Detection ◽  
Ssdna Aptamer ◽  
Aptamer Assay ◽  
Small Molecule Detection ◽  
Surface Changes

A universal aptamer-based sensing strategy is proposed using DNA modified nanocarriers and Resistive Pulse Sensing for the rapid and label free detection of small molecules. The surface of a magnetic nanocarrier was first modified with a ssDNA aka linker which is designed to be partially complimentary in sequence to a ssDNA aptamer. The aptamer and linker form a stable dsDNA complex on the nanocarriers surface. Upon the addition of the target molecule, a conformational change takes place where the aptamer preferentially binds to the target over the linker; causing the aptamer to be released into solution. The RPS measures the change in velocity of the nanocarrier as its surface changes from dsDNA to ssDNA, and its velocity is used as a proxy for the concentration of the target. We illustrate the versatility of the assay by demonstrating the detection of the antibiotic Moxifloxacin, and chemotherapeutics Imatinib and Irinotecan.

scholarly journals Rapid label-free SERS detection of foodborne pathogenic bacteria based on hafnium ditelluride-Au nanocomposites

2020 ◽  
Vol 13 (05) ◽  
pp. 2041004 ◽  
Author(s):  
Yang Li ◽  
Yanxian Guo ◽  
Binggang Ye ◽  
Zhengfei Zhuang ◽  
Peilin Lan ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Limit Of Detection ◽  
Principal Component ◽  
High Sensitivity ◽  
Chemical Mechanism ◽  
Sers Substrate ◽  
Label Free ◽  
Label Free Detection ◽  
Surface Enhanced Raman ◽  
Foodborne Pathogenic Bacteria

Two-dimensional (2D) nanomaterials have captured an increasing attention in biophotonics owing to their excellent optical features. Herein, 2D hafnium ditelluride (HfTe[Formula: see text], a new member of transition metal tellurides, is exploited to support gold nanoparticles fabricating HfTe2-Au nanocomposites. The nanohybrids can serve as novel 2D surface-enhanced Raman scattering (SERS) substrate for the label-free detection of analyte with high sensitivity and reproducibility. Chemical mechanism originated from HfTe2 nanosheets and the electromagnetic enhancement induced by the hot spots on the nanohybrids may largely contribute to the superior SERS effect of HfTe2-Au nanocomposites. Finally, HfTe2-Au nanocomposites are utilized for the label-free SERS analysis of foodborne pathogenic bacteria, which realize the rapid and ultrasensitive Raman test of Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Salmonella with the limit of detection of 10 CFU/mL and the maximum Raman enhancement factor up to [Formula: see text]. Combined with principal component analysis, HfTe2-Au-based SERS analysis also completes the bacterial classification without extra treatment.

scholarly journals Label-free detection of Phytophthora ramorum using surface-enhanced Raman spectroscopy

The Analyst ◽  
2015 ◽  
Vol 140 (21) ◽  
pp. 7254-7262 ◽  
Author(s):  
Sezin Yüksel ◽  
Lydia Schwenkbier ◽  
Sibyll Pollok ◽  
Karina Weber ◽  
Dana Cialla-May ◽  
...  
Keyword(s):  
Surface Enhanced Raman Spectroscopy ◽  
Analytical Tool ◽  
Phytophthora Ramorum ◽  
Label Free ◽  
Specific Detection ◽  
Real Samples ◽  
Label Free Detection ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Species Specific

Label-free and species-specific detection of the plant pathogen Phytophthora ramorum from real samples employing SERS as an analytical tool.

Label-Free Detection of Native Proteins by Surface-Enhanced Raman Spectroscopy Using Iodide-Modified Nanoparticles

2014 ◽  
Vol 86 (4) ◽  
pp. 2238-2245 ◽  
Author(s):  
Li-Jia Xu ◽  
Cheng Zong ◽  
Xiao-Shan Zheng ◽  
Pei Hu ◽  
Jia-Min Feng ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Label Free ◽  
Native Proteins ◽  
Label Free Detection ◽  
Surface Enhanced ◽  
Surface Enhanced Raman
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