Improved Detection of Hg2+ in Aqueous Solution with High Sensitivity and Selectivity by Using Mercury-Specific DNA, Sybr Green I and Gold Nanoparticles

2011 ◽  
Vol 239-242 ◽  
pp. 934-939
Author(s):  
Hui Xu ◽  
Shuli Gao ◽  
Jian Nong Chen ◽  
Quan Wen Liu
Keyword(s):  
Gold Nanoparticles ◽  
High Sensitivity ◽  
Sybr Green ◽  
Sybr Green I ◽  
Fluorescence Signal ◽  
Potassium Ions ◽  
Label Free ◽  
Turn On ◽  
Sensitivity And Selectivity ◽  
Fluorescence Turn On

We report a label-free, fast, fluorescence turn on assay for Hg2+detecton by using mercury-specific DNA (MSD), Sybr Green I (SG) and gold nanoparticles (AuNPs). SG efficiently discriminates MSD and MSD/Hg2+complex. The addition of gold nanoparticle decreases the background fluorescence signal further for MSD. The fluorescence intensity of MSD/Hg2+complex keeps constant after addition of AuNPs. This property improves the signal-to-background ratio and decreases the detection limitation further. In addition, the method shows improved selectivity compared with that in the absence of AuNPs. This strategy could be applied to the detection of potassium ions and showed good generality.

Nitrogen doped carbon dots: mechanism investigation and their application for label free CA125 analysis

2019 ◽  
Vol 7 (19) ◽  
pp. 3053-3058 ◽  
Author(s):  
Yuanyuan Liu ◽  
Liping Jiang ◽  
Bijun Li ◽  
Xinyue Fan ◽  
Wei Wang ◽  
...  
Keyword(s):  
Nitrogen Doping ◽  
Competitive Adsorption ◽  
High Sensitivity ◽  
Label Free ◽  
Nitrogen Doped ◽  
Microwave Assisted ◽  
Turn On ◽  
Sensitivity And Selectivity ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

Nitrogen-doped CDs (N-CDs) were firstly prepared by using pear juice as the carbon source and ethanediamine as a nitrogen doping precursor with a microwave assisted pyrolysis technique. Based on the fluorescence recovery induced by competitive adsorption and desorption, a label-free “turn on” fluorescence assay with high sensitivity and selectivity was proposed for the analysis of CA125.

A sensitive biosensor with a DNAzyme for lead(ii) detection based on fluorescence turn-on

The Analyst ◽  
2015 ◽  
Vol 140 (13) ◽  
pp. 4642-4647 ◽  
Author(s):  
Yang Guo ◽  
Junting Li ◽  
Xiaoqian Zhang ◽  
Yanli Tang
Keyword(s):  
High Sensitivity ◽  
Optical Biosensor ◽  
Lead Ions ◽  
Turn On ◽  
Sensitivity And Selectivity ◽  
Fluorescence Turn On

A new optical biosensor for detection of lead ions has been constructed based on fluorescence turn-on, which demonstrates high sensitivity and selectivity without any additional procedures.

Amplified Fluorescence Turn-on Assay for Mercury(II) Based on Conjugated Polyfluorene Derivatives and Nanospheres

2008 ◽  
Vol 1134 ◽  
Author(s):  
Yusong Wang ◽  
Bin Liu
Keyword(s):  
Metal Ion ◽  
Resonance Energy Transfer ◽  
Fluorescence Emission ◽  
Resonance Energy ◽  
High Sensitivity ◽  
Probe Design ◽  
Turn On ◽  
Sensitivity And Selectivity ◽  
Fluorescence Turn On ◽  
Polyfluorene Derivatives

AbstractDetection of mercury with high sensitivity and selectivity constitutes a significant research concern. Here, we report an amplified fluorescence turn-on assay for mercury(II) with an improved performance. This sensing system takes advantage of optically amplifying fluorescent conjugated polyfluorene derivatives and DNA immobilized silica nanospheres (NSs) in addition to the specific thymine- mercury(II)-thymine(T- Hg2+-T) interaction. The employment of ion-specific T- Hg2+-T coordination increases the melting temperature (Tm) of the double-stranded DNA (dsDNA) on the hybridized NS surface. After thermal washing at 45 °C, the Hg2+ treated sample (dsDNA-NS) was effectively differentiated from that treated with nonspecific ions through monitoring fluorescence emission of fluorescein (Fl) labeled target DNA remained on the NS surface. Finally, a cationic conjugated polyfluorene derivative (CCP) was introduced to electrostatically associate with the DNA molecules on the NS surface, resulting in an amplified Fl signal via fluorescence resonance energy transfer (FRET) from the CCP to the dye molecule. In comparison with the use of Fl alone as a signal reporter, the presence of CCP significantly enhances the detection fluorescence intensity, reduces false-positive signal, and improves the detection selectivity for mercury(II). Further improvement in the probe design could yield more efficient metal ion sensors, which have the potential to be operated at room temperature and for the detection of other metal ions besides mercury(II).

A turn-on luminescent probe for Fe3+ and ascorbic acid with logic gate operation based on a zinc(ii)-based metal–organic framework

2020 ◽  
Vol 44 (21) ◽  
pp. 8728-8735 ◽  
Author(s):  
Jing Tang ◽  
Doudou Feng ◽  
Jie Yang ◽  
Xuehui Ma ◽  
Xiao-Qing Wang
Keyword(s):  
Metal Organic Framework ◽  
Logic Gate ◽  
High Sensitivity ◽  
Luminescent Probe ◽  
Gate Operation ◽  
Turn On ◽  
Sensitivity And Selectivity ◽  
Metal Organic ◽  
Fluorescence Turn On ◽  
Organic Framework

A zinc(ii)-based metal–organic framework exhibits fluorescence turn-on behaviour for Fe3+ and AA with high sensitivity and selectivity.

scholarly journals Simple and Label-Free Fluorescent Detection of Melamine Based on Melamine–Thymine Recognition

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2968 ◽  
Author(s):  
Hualin Yang ◽  
Jiujun Wang ◽  
Qinghua Wu ◽  
Yun Wang ◽  
Li Li ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Chain Structure ◽  
Sybr Green ◽  
Sybr Green I ◽  
Fluorescent Detection ◽  
Fluorescence Signal ◽  
Label Free ◽  
Protein Levels ◽  
Fluorescent Method ◽  
Milk Adulteration

In the past few years, melamine has been illegally added into dairy products to increase the apparent crude protein levels. If humans or animals drink the milk adulteration of melamine, it can form insoluble melamine–cyanurate crystals in their kidneys which causes kidney damage or even death. In the present work, we constructed a simple and label-free fluorescent method for melamine detection based on melamine-thymine recognition. SYBR Green I was utilized as a reporter for this method as it did not require any modification or expensive equipment. In the absence of melamine, polythymine DNA was digested by Exo I, which caused a decrease in the fluorescence signal. In the presence of melamine, the polythymine DNA was able to fold into a double chain structure, however this was done with the help of T-melamine-T mismatches to prevent degradation. Then, the SYBR Green I combined with the double-stranded DNA to result in an intense fluorescence signal. The limit of detection in this method was 1.58 μM, which satisfied the FDA standards. This method also had a good linear relationship within the range of 10–200 μM. In addition, this new method has a good selectivity to distinguish melamine from the component of milk. As a result, we developed a simple and highly selectivity method for melamine detection.

Label-free fluorescence assay coupled exonuclease reaction and SYBR Green I for the detection of T4 polynucleotide kinase activity

2020 ◽  
Vol 12 (6) ◽  
pp. 807-812
Author(s):  
Xu Wu ◽  
Shuyi He ◽  
Julia Xiaojun Zhao
Keyword(s):  
Kinase Activity ◽  
Sybr Green ◽  
Fluorescence Assay ◽  
Sybr Green I ◽  
Label Free ◽  
Cleavage Reaction ◽  
Polynucleotide Kinase ◽  
T4 Polynucleotide Kinase

A sensitive label-free fluorescence assay for monitoring T4 polynucleotide kinase (T4 PNK) activity and inhibition was developed based on a coupled λ exonuclease cleavage reaction and SYBR Green I.

scholarly journals Nucleic-Acid-Binding Chromophores as Efficient Indicators of Aptamer-Target Interactions

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Kwabena Sarpong ◽  
Bhaskar Datta
Keyword(s):  
Nucleic Acid ◽  
High Sensitivity ◽  
Covalent Modification ◽  
Fluorescence Signal ◽  
Nucleic Acid Binding ◽  
Sensitivity And Selectivity ◽  
Target Molecules ◽  
Diagnostic Applications ◽  
The Stability ◽  
Simple Format

The binding affinity and specificity of nucleic acid aptamers have made them valuable candidates for use as sensors in diagnostic applications. In particular, chromophore-functionalized aptamers offer a relatively simple format for detection and quantification of target molecules. We describe the use of nucleic-acid-staining reagents as an effective tool for detecting and signaling aptamer-target interactions. Aptamers varying in size and structure and targeting a range of molecules have been used in conjunction with commercially available chromophores to indicate and quantify the presence of cognate targets with high sensitivity and selectivity. Our assay precludes the covalent modification of nucleic acids and relies on the differential fluorescence signal of chromophores when complexed with aptamers with or without their cognate target. We also evaluate factors that are critical for the stability of the complex between the aptamer and chromophore in presence or absence of target molecules. Our results indicate the possibility of controlling those factors to enhance the sensitivity of target detection by the aptamers used in such assays.

A highly sensitive turn-on ratiometric luminescent probe based on postsynthetic modification of Tb3+@Cu-MOF for H2S detection

2017 ◽  
Vol 5 (38) ◽  
pp. 9943-9951 ◽  
Author(s):  
Xubin Zheng ◽  
Ruiqing Fan ◽  
Yang Song ◽  
Ani Wang ◽  
Kai Xing ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Luminescent Probe ◽  
Turn On ◽  
Postsynthetic Modification ◽  
Highly Sensitive ◽  
Sensitivity And Selectivity ◽  
H2s Detection

A novel probe, designed and prepared through PSM of Cu-MOFs and Tb3+ions, shows high sensitivity and selectivity for H2S.

Sign in / Sign up

Export Citation Format

Share Document