scholarly journals Highly sensitive detection of Cr(VI), Pb(II) and Cd(II) ions by a new fluorescent sensor based on 4-amino-3-hydroxynaphthalene sulfonic acid-doped polypyrrole

2020 ◽  
Vol 39 (2) ◽  
pp. 139
Author(s):  
Mohamed Lamine Sall ◽  
Abdou Karim Diaw ◽  
Diariatou Gningue-Sall ◽  
Mehmet Ali Oturan ◽  
Jean-Jacques Aaron
Keyword(s):  
Fluorescence Quenching ◽  
Sulfonic Acid ◽  
Fluorescence Spectra ◽  
Fluorescent Sensor ◽  
High Sensitivity ◽  
Metallic Ions ◽  
Excitation Peak ◽  
Main Band ◽  
Main Emission Peak ◽  
Highly Sensitive Detection

A new electrosynthesized, fluorescent 4-amino-3-hydroxynaphthalene-1-sulfonic acid-doped polypyrrole (AHNSA-PPy) was used for the detection of Cr(VI), Pb(II) and Cd(II) heavy metallic ions. The optical properties of AHNSA-PPy were studied by UV-VIS absorption and fluorescence spectrometry in diluted DMSO solutions. UV-VIS spectrum showed a main band at 260 nm, a moderate band at 240 nm, and shoulders at 285, 295, 320 and 360 nm, whereas the fluorescence spectrum presented an excitation peak at 330 nm and a main emission peak at 390 nm with a shoulder at 295 nm. The effects of heavy metallic ions, including Cr(VI), Pb(II), and Cd(II), on the AHNSA-PPy UV-VIS absorption and fluorescence spectra were investigated. AHNSA-PPy fluorescence spectra were strongly quenched upon increasing the Cr(VI), Pb(II) and Cd(II) concentrations. Linear Stern-Volmer relationships were established, and polynomial equations for Pb(II) and Cd(II) were obeyed, indicating the existence of a AHNSA-PPy dynamic fluorescence quenching mechanism for Cr(VI) and a combination of dynamic and static fluorescence quenching for Pb(II) and Cd(II). The AHNSA-PPy sensor showed high sensitivity for fluorescence detection of the three heavy metallic ions, with very low limits of detection (3σ) of 1.4 nM for Cr(VI), 2.7 nM for Cd(II) and 2.6 nM for Pb(II). Therefore, this very sensitive quenching fluorimetric sensor is proposed for the detection of trace, toxic heavy metallic ions in the environment.

A phthalocyanine-based fluorescent sensor for Zn2+ ion

2013 ◽  
Vol 17 (01n02) ◽  
pp. 99-103 ◽  
Author(s):  
Hui He ◽  
Jian-Yong Liu ◽  
Dennis K.P. Ng
Keyword(s):  
Metal Ions ◽  
Spectral Properties ◽  
Fluorescence Spectra ◽  
Near Infrared ◽  
Fluorescent Sensor ◽  
High Sensitivity ◽  
Absorption And Fluorescence Spectra

This paper describes the preparation and spectral properties of a near-infrared fluorophore in which two bis(2-picolyl)amino moieties are axially linked to a silicon(IV) phthalocyanine core. The effects of various metal ions on its absorption and fluorescence spectra have been examined. The results indicate that this compound shows a high sensitivity and moderate selectivity toward Zn2+ ion.

scholarly journals A sensitive fluorescent sensor for highly sensitive detection of trace water in organic solvents based on substituted imidazole

2021 ◽  
Author(s):  
Huiqian Li ◽  
Weijian Xue ◽  
Jinping Wang ◽  
Jie Ma ◽  
Bing Zhao ◽  
...  
Keyword(s):  
Fluorescence Spectra ◽  
Fluorescent Sensor ◽  
Important Change ◽  
Red Shift ◽  
Imidazole Derivative ◽  
Absorption And Fluorescence Spectra ◽  
Highly Sensitive ◽  
Initial Discovery ◽  
Highly Sensitive Detection ◽  
Trace Water

Abstract A novel substituted imidazole derivative 1a with carboxyl and quinoline structure has been designed and synthesized. And our initial discovery is that this compound can effectively detect trace amounts of water in ethanol. And the metal in solution couldn’t affect the absorption and fluorescence Spectra of 1a. With the addition of water, the energy band appears a red-shift from 330nm to 355nm in the absorption spectra. And the emission spectrum undergoes an important change in its fluorescent effect in the presence of water. Furthermore, absorption peak of 1a displays a red-shift with increasing pH from 2.31 to 10.72. All available data (absorption and emission) strongly support the possible mechanism. Due to the pronounced fluorescence changing property, the substituted imidazole derivative 1a could be utilized as fluorescent probes for quantifying trace amount of water in ethanol. Graphic abstract

scholarly journals Integrating gold nanoclusters, folic acid and reduced graphene oxide for nanosensing of glutathione based on “turn-off” fluorescence

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xin Yi Wong ◽  
Daniel Quesada-González ◽  
Sivakumar Manickam ◽  
Siu Yee New ◽  
Kasturi Muthoosamy ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Folic Acid ◽  
Fluorescence Quenching ◽  
Reduced Graphene Oxide ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Gold Nanoclusters ◽  
High Sensitivity ◽  
Sample Treatment ◽  
Reduced Graphene

AbstractGlutathione (GSH) is a useful biomarker in the development, diagnosis and treatment of cancer. However, most of the reported GSH biosensors are expensive, time-consuming and often require complex sample treatment, which limit its biological applications. Herein, a nanobiosensor for the detection of GSH using folic acid-functionalized reduced graphene oxide-modified BSA gold nanoclusters (FA-rGO-BSA/AuNCs) based on the fluorescence quenching interactions is presented. Firstly, a facile and optimized protocol for the fabrication of BSA/AuNCs is developed. Functionalization of rGO with folic acid is performed using EDC/NHS cross-linking reagents, and their interaction after loading with BSA/AuNCs is demonstrated. The formation of FA-rGO, BSA/AuNCs and FA-rGO-BSA/AuNCs are confirmed by the state-of-art characterization techniques. Finally, a fluorescence turn-off sensing strategy is developed using the as-synthesized FA-rGO-BSA/AuNCs for the detection of GSH. The nanobiosensor revealed an excellent sensing performance for the detection of GSH with high sensitivity and desirable selectivity over other potential interfering species. The fluorescence quenching is linearly proportional to the concentration of GSH between 0 and 1.75 µM, with a limit of detection of 0.1 µM under the physiological pH conditions (pH 7.4). Such a sensitive nanobiosensor paves the way to fabricate a “turn-on” or “turn-off” fluorescent sensor for important biomarkers in cancer cells, presenting potential nanotheranostic applications in biological detection and clinical diagnosis.

scholarly journals A Novel Thiosemicarbazide-Based Fluorescent Chemosensor for Hypochlorite in Near-Perfect Aqueous Solution and Zebrafish

Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 65
Author(s):  
Minji Lee ◽  
Donghwan Choe ◽  
Soyoung Park ◽  
Hyeongjin Kim ◽  
Soomin Jeong ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Reactive Oxygen Species ◽  
Aqueous Solution ◽  
Fluorescence Quenching ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Ionization Mass ◽  
Oxygen Species ◽  
Marked Selectivity ◽  
Uv Visible

A novel thiosemicarbazide-based fluorescent sensor (AFC) was developed. It was successfully applied to detect hypochlorite (ClO−) with fluorescence quenching in bis-tris buffer. The limit of detection of AFC for ClO− was analyzed to be 58.7 μM. Importantly, AFC could be employed as an efficient and practical fluorescent sensor for ClO− in water sample and zebrafish. Moreover, AFC showed a marked selectivity to ClO− over varied competitive analytes with reactive oxygen species. The detection process of AFC to ClO− was illustrated by UV–visible and fluorescent spectroscopy and electrospray ionization–mass spectrometry (ESI–MS).

scholarly journals Highly sensitive detection of nitrobenzene by a series of fluorescent 2D zinc(ii) metal–organic frameworks with a flexible triangular ligand

RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 23975-23984
Author(s):  
Xue Yang ◽  
Yixia Ren ◽  
Hongmei Chai ◽  
Xiufang Hou ◽  
Zhixiang Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Metal Organic Frameworks ◽  
High Sensitivity ◽  
Fluorescent Sensors ◽  
Sensitive Detection ◽  
Donor Ligands ◽  
Highly Sensitive ◽  
Metal Organic ◽  
Highly Sensitive Detection

Four fluorescent 2D Zn-MOFs based on a flexible triangular ligand and linear N-donor ligands are hydrothermally prepared and used to detect nitrobenzene in aqueous solution with high sensitivity, demonstrating their potential as fluorescent sensors.

scholarly journals A two-stage amplified PZT sensor for monitoring lung and heart sounds in discharged pneumonia patients

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Hongbin Chen ◽  
Shuai Yu ◽  
Haiyang Liu ◽  
Jie Liu ◽  
Yongguang Xiao ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Cost Effective ◽  
High Ratio ◽  
Heart Sounds ◽  
Two Stage ◽  
Diagnosis And Prognosis ◽  
Sensor Device ◽  
Cost Effective Alternative ◽  
A Charge ◽  
Highly Sensitive Detection

AbstractAssessment of lung and heart states is of critical importance for patients with pneumonia. In this study, we present a small-sized and ultrasensitive accelerometer for continuous monitoring of lung and heart sounds to evaluate the lung and heart states of patients. Based on two-stage amplification, which consists of an asymmetric gapped cantilever and a charge amplifier, our accelerometer exhibited an extremely high ratio of sensitivity to noise compared with conventional structures. Our sensor achieves a high sensitivity of 9.2 V/g at frequencies less than 1000 Hz, making it suitable to use to monitor weak physiological signals, including heart and lung sounds. For the first time, lung injury, heart injury, and both lung and heart injuries in discharged pneumonia patients were revealed by our sensor device. Our sound sensor also successfully tracked the recovery course of the discharged pneumonia patients. Over time, the lung and heart states of the patients gradually improved after discharge. Our observations were in good agreement with clinical reports. Compared with conventional medical instruments, our sensor device provides rapid and highly sensitive detection of lung and heart sounds, which greatly helps in the evaluation of lung and heart states of pneumonia patients. This sensor provides a cost-effective alternative approach to the diagnosis and prognosis of pneumonia and has the potential for clinical and home-use health monitoring.

Highly sensitive detection of Cr(vi) in groundwater by bimetallic NiFe nanoparticles

2017 ◽  
Vol 9 (6) ◽  
pp. 1031-1037 ◽  
Author(s):  
Jingtao Liu ◽  
Yu Ding ◽  
Lifei Ji ◽  
Xin Zhang ◽  
Fengchun Yang ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Hexavalent Chromium ◽  
Low Cost ◽  
High Sensitivity ◽  
Sensitive Detection ◽  
Toxic Heavy Metal ◽  
Metal Pollutants ◽  
Highly Sensitive ◽  
Highly Sensitive Detection ◽  
Heavy Metal Pollutants

Hexavalent chromium (Cr(vi)) is one of the most toxic heavy metal pollutants in groundwater, and thus the detection of Cr(vi) with high sensitivity, accuracy, and simplicity and low cost is of great importance.

scholarly journals A water-soluble fluorescent chemosensor based on Asp functionalized naphthalimide for successive detection Fe3+ and H2PO4−

2018 ◽  
Vol 96 (4) ◽  
pp. 363-370 ◽  
Author(s):  
You-Ming Zhang ◽  
Xiao-Peng Chen ◽  
Guo-Yan Liang ◽  
Kai-Peng Zhong ◽  
Hong Yao ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Metal Ions ◽  
Aspartic Acid ◽  
High Selectivity ◽  
Fluorescent Sensor ◽  
Water Solution ◽  
Water Soluble ◽  
Selective Recognition ◽  
Actual Usage ◽  
Quenching Process

The selective recognition of target ions in water is very important and the development of novel water-soluble chemosensor is still an intriguing challenge. Herein, a novel water-soluble fluorescent sensor based on aspartic acid (Asp) functionalized 1,8-naphthalimide derivative (Asp-NI) has been designed and synthesized. The sensor Asp-NI could dissolve in water and successively detect Fe3+ and H2PO4− in water solution with high selectivity and sensitivity. The detection limits are 4.97 × 10−7 mol/L for Fe3+ and 5.27 × 10−6 mol/L for H2PO4−. Other coexistent competitive metal ions (Hg2+, Ag+, Ca2+, Cu2+, Co2+, Ni2+, Cd2+, Pb2+, Zn2+, Cr3+, and Mg2+) showed no interference in the Fe3+ detection process. The sensor Asp-NI could act as a Fe3+ and H2PO4− controlled “On–Off–On” fluorescent switch. More interestingly, the Fe3+ induced fluorescence quenching process could be totally reversed by the addition of H2PO4−, this “On–Off–On” switching process could be repeated several times with little fluorescence loss. Notably, the actual usage of sensor Asp-NI was further demonstrated by test kits.

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