scholarly journals Naked-eye detection as a universal approach to lower the limit of detection of enzyme-linked immunoassays

2016 ◽  
Vol 408 (13) ◽  
pp. 3389-3393 ◽  
Author(s):  
Erin F. O’Connor ◽  
Sureyya Paterson ◽  
Roberto de la Rica
Keyword(s):  
Limit Of Detection ◽  
Eye Detection ◽  
Naked Eye ◽  
Universal Approach ◽  
Naked Eye Detection

Naked-Eye Detection of Mercury Ions from Morphological Transition of Silver Nanocubes: Tuning Sensitivity Using Co-Staining Agent

2021 ◽  
Vol 21 (4) ◽  
pp. 2123-2131
Author(s):  
Alagan Jeevika ◽  
Dhesingh Ravi Shankaran
Keyword(s):  
Color Change ◽  
Limit Of Detection ◽  
Low Cost ◽  
Toxic Metal ◽  
Face Centered Cubic ◽  
Mercury Ions ◽  
Eye Detection ◽  
Naked Eye ◽  
Silver Nanocubes ◽  
Naked Eye Detection

A simple, low-cost and highly selective nanosensor was developed for naked-eye detection of mercury ions (Hg2+) based on Eosin/silver nanocubes (Eosin/AgNCbs). Silver nanocubes (AgNCbs) were synthesized by polyol assisted chemical method. HR-TEM result shows the formed AgNCbs have a mean diameter of 84±0.005 nM (diagonally measured) and edge length of 55±0.01 nM. XRD result confirms that the AgNCbs are single crystalline in nature with a phase structure of face centered cubic (FCC) of silver. On interaction of Hg2+, AgNCbs exhibits a color change from gray to black up to 16.67 μM of Hg2+ owed to the formation of solid like bimetallic complex of Ag/Hg amalgam. The selectivity of AgNCbs was evaluated with several other toxic metal ions including, Mg2+, Ba2+, Ca4+, Pb2+, Cd4+, Zn2+, Co2+, Cu2+, K+ and Ni2+ and found good selectivity towards Hg2+. The sensitivity of the AgNCbs sensor system was tuned by using Eosin as a co-staining agent. The Eosin/AgNCbs showed a limit of detection of 60±0.050 nM with the color change from orange to purple. The results suggests that the Eosin/AgNCbs nanosensor exhibits good selectivity, sensitivity, repeatability and rapid response, which could be explored for real-time detection of Hg2+ in environmental and biological samples.

Naked-Eye Detection of Hg(II) Ions by Visible Light-Induced Polymerization Initiated by a Hg(II)-Selective Photoredox Catalyst

2021 ◽  
Author(s):  
Hyungwook Kim ◽  
Young Jae Jung ◽  
Jungkyu K. Lee
Keyword(s):  
Visible Light ◽  
Signal Amplification ◽  
Eye Detection ◽  
Naked Eye ◽  
Turn On ◽  
Novel Strategy ◽  
Amplification Strategy ◽  
Naked Eye Detection

We developed a novel strategy for signal amplification strategy using a visible light-induced photopolymerization, initiated by a selective turn-on photoredox catalyst. As photoredox catalysts, fluorescein derivatives are able to initiate...

Naked eye detection and measurement of fluoride concentration in groundwater using novel synthesized receptor

2021 ◽  
Vol 328 ◽  
pp. 112776
Author(s):  
Yogendra Singh Solanki ◽  
Priya Yadav ◽  
Madhu Agarwal ◽  
Ragini Gupta ◽  
Sanjeev Gupta ◽  
...  
Keyword(s):  
Fluoride Concentration ◽  
Eye Detection ◽  
Naked Eye ◽  
Naked Eye Detection

Cholesterol decorated pyridinium urea and carbamate as π-gelators for selective recognition of F- ions

2021 ◽  
Vol 05 ◽  
Author(s):  
Santanu Panja ◽  
Kumaresh Ghosh
Keyword(s):  
Sol Gel ◽  
Functional Materials ◽  
Materials Chemistry ◽  
Eye Detection ◽  
Fluoride Ions ◽  
Biologically Relevant ◽  
Design And Synthesis ◽  
Naked Eye ◽  
Visual Sensing ◽  
Naked Eye Detection

Aim: Design and synthesis of new molecules capable of forming self-assembled gels are indispensable to harvest new functional materials. Supramolecular gels have potential in many areas particularly in biology and materials chemistry. Of the different types of applications, visual sensing of biologically relevant ionic analytes is a fairly recent trend. Here we describe naked eye detection of fluoride ions involving sol-gel methodology. Methods: To execute this, cholesterol substituted pyridinium salts 1-4 have been designed and synthesized of which compounds 3 and 4 served as potential gelators for the naked eye detection of F- ions in DMSO and DMSO-H2O (1:1, v/v) respectively. Results: Gelation study reveals that not only the aromatic surface is crucial for the self-aggregation of molecules via π-π stacking interactions, but also polarity, rigidity and conformational flexibility of the molecules that govern the intermolecular association of gelators are important. Conclusion: Moreover, incorporation of fluorophores (naphthalene) as aromatic surface in the molecular designs, promotes the gelator molecules to execute sensing behavior for F- with high degree of sensitivity in solution phase also.

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