scholarly journals Phenosafranin-Based Colorimetric-Sensing Platform for Nitrite Detection Enabled by Griess Assay

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1501
Author(s):  
Jingzhou Hou ◽  
Huixiang Wu ◽  
Xin Shen ◽  
Chao Zhang ◽  
Changjun Hou ◽  
...  
Keyword(s):  
Detection Limit ◽  
Color Change ◽  
Quantitative Detection ◽  
Optimal Detection ◽  
Colorimetric Sensing ◽  
Promising Candidate ◽  
Sensing Platform ◽  
Acidic Conditions ◽  
Hcl Concentration ◽  
Griess Assay

A facile and effective colorimetric-sensing platform based on the diazotization of phenosafranin for the detection of NO 2 − under acidic conditions using the Griess assay is presented. Diazotization of commercial phenosafranin produces a color change from purplish to blue, which enables colorimetric quantitative detection of NO 2 − . Optimal detection conditions were obtained at a phenosafranin concentration of 0.25 mM, HCl concentration of 0.4 M, and reaction time of 20 min. Under the optimized detection conditions, an excellent linearity range from 0 to 20 μM was obtained with a detection limit of 0.22 μM. Favorable reproducibility and selectivity of the colorimetric sensing platform toward NO 2 − were also verified. In addition, testing spiked ham sausage, bacon, and sprouts samples demonstrated its excellent practicability. The presented colorimetric sensing platform is a promising candidate for the detection of NO 2 − in real applications.

scholarly journals Single-Atom Fe-Anchored Nano-Diamond With Enhanced Dual-Enzyme Mimicking Performance for H2O2 and Glutathione Detection

2022 ◽  
Vol 9 ◽  
Author(s):  
Ying Liu ◽  
Jianghong Yan ◽  
Yu Huang ◽  
Zhiheng Sun ◽  
Huijing Zhang ◽  
...  
Keyword(s):  
Detection Limit ◽  
Color Change ◽  
Colorimetric Method ◽  
Free Radical Scavenger ◽  
The Body ◽  
Single Atom ◽  
Iron Oxide Nanoparticle ◽  
Radical Scavenger ◽  
Colorimetric Sensing ◽  
One Pot

Glutathione (GSH) is an important antioxidant and free radical scavenger that converts harmful toxins into harmless substances and excretes them out of the body. In the present study, we successfully prepared single-atom iron oxide-nanoparticle (Fe-NP)-modified nanodiamonds (NDs) named Fe-NDs via a one-pot in situ reduction method. This nanozyme functionally mimics two major enzymes, namely, peroxidase and oxidase. Accordingly, a colorimetric sensing platform was designed to detect hydrogen peroxide (H2O2) and GSH. Owing to their peroxidase-like activity, Fe-NDs can oxidize colorless 3,3′,5,5′-tetramethylbenzidine (TMB) into blue with sufficient linearity at H2O2 concentrations of 1–60 μM and with a detection limit of 0.3 μM. Furthermore, using different concentrations of GSH, oxidized TMB can be reduced to TMB, and the color change from blue to nearly colorless can be observed by the naked eye (linear range, 1–25 μM; detection limit, 0.072 μM). The established colorimetric method based on oxidase-like activity can be successfully used to detect reduced GSH in tablets and injections with good selectivity and high sensitivity. The results of this study exhibited reliable consistency with the detection results obtained using high-performance liquid chromatography (HPLC). Therefore, the Fe-NDs colorimetric sensor designed in this study offers adequate accuracy and sensitivity.

Ionic liquid tuned titanium dioxide nanostructures as an efficient colorimetric sensing platform for dopamine detection

2021 ◽  
Vol 262 ◽  
pp. 124289
Author(s):  
Umar Nishan ◽  
Ujala Sabba ◽  
Abdur Rahim ◽  
Muhammad Asad ◽  
Mohibullah Shah ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Titanium Dioxide ◽  
Colorimetric Sensing ◽  
Dopamine Detection ◽  
Sensing Platform

scholarly journals Ce-MOF with Intrinsic Haloperoxidase-Like Activity for Ratiometric Colorimetric Detection of Hydrogen Peroxide

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 204
Author(s):  
Yanyan Cheng ◽  
Ling Liang ◽  
Fanggui Ye ◽  
Shulin Zhao
Keyword(s):  
Structural Characteristics ◽  
Metal Organic Framework ◽  
Colorimetric Detection ◽  
Mixed Valence ◽  
Bromophenol Blue ◽  
Phenol Red ◽  
Chromogenic Substrate ◽  
Colorimetric Sensing ◽  
Sensing Platform ◽  
Metal Organic

Metal–organic framework (MOF) nanozymes, as emerging members of the nanozymes, have received more and more attention due to their composition and structural characteristics. In this work, we report that mixed-valence state Ce-MOF (MVCM) has intrinsic haloperoxidase-mimicking activity. MVCM was synthesized by partial oxidation method using Ce-MOF as a precursor. In the presence of H2O2 and Br−, MVCM can catalyze oxidative bromination of chromogenic substrate phenol red (PR) to produce the blue product bromophenol blue (Br4PR), showing good haloperoxidase-like activity. Because of the special chromogenic substrate, we constructed a ratiometric colorimetric-sensing platform by detecting the absorbance of the MVCM-(PR, Br−) system at wavelengths of 590 and 430, for quantifying H2O2, where the detection limit of the H2O2 is 3.25 μM. In addition, the haloperoxidase-mimicking mechanism of the MVCM is proposed. Moreover, through enzyme kinetics monitoring, the Km (H2O2 and NH4Br) of the MVCM is lower than that of cerium oxide nanomaterials, indicating that the MVCM has a stronger binding affinity for H2O2 and NH4Br than other materials. This work provides more application prospects for the development of nanozymes in the field of biosensors in the future.

scholarly journals Plasmonic Sensing Studies of a Gas-Phase Cystic Fibrosis Marker in Moisture Laden Air

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3776
Author(s):  
Libin Sun ◽  
Douglas Conrad ◽  
Drew A. Hall ◽  
Kurt D. Benkstein ◽  
Steve Semancik ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Detection Limit ◽  
Gas Phase ◽  
Localized Surface Plasmon ◽  
Exhaled Breath ◽  
Nanohole Array ◽  
Dry Air ◽  
Plasmonic Sensing ◽  
Sensing Platform ◽  
The Status

A plasmonic sensing platform was developed as a noninvasive method to monitor gas-phase biomarkers related to cystic fibrosis (CF). The nanohole array (NHA) sensing platform is based on localized surface plasmon resonance (LSPR) and offers a rapid data acquisition capability. Among the numerous gas-phase biomarkers that can be used to assess the lung health of CF patients, acetaldehyde was selected for this investigation. Previous research with diverse types of sensing platforms, with materials ranging from metal oxides to 2-D materials, detected gas-phase acetaldehyde with the lowest detection limit at the µmol/mol (parts-per-million (ppm)) level. In contrast, this work presents a plasmonic sensing platform that can approach the nmol/mol (parts-per-billion (ppb)) level, which covers the required concentration range needed to monitor the status of lung infection and find pulmonary exacerbations. During the experimental measurements made by a spectrometer and by a smartphone, the sensing examination was initially performed in a dry air background and then with high relative humidity (RH) as an interferent, which is relevant to exhaled breath. At a room temperature of 23.1 °C, the lowest detection limit for the investigated plasmonic sensing platform under dry air and 72% RH conditions are 250 nmol/mol (ppb) and 1000 nmol/mol (ppb), respectively.

Two Orders of Magnitude Improvement in the Detection Limit of Droplet-Based Micro-Magnetofluidics with Planar Hall Effect Sensors

2021 ◽  
Vol 6 (1) ◽  
pp. 47
Author(s):  
Julian Schütt ◽  
Rico Illing ◽  
Oleksii Volkov ◽  
Tobias Kosub ◽  
Pablo Nicolás Granell ◽  
...  
Keyword(s):  
Detection Limit ◽  
Hall Effect ◽  
State Of The Art ◽  
Limit Of Detection ◽  
Research Field ◽  
High Throughput Analysis ◽  
Planar Hall Effect ◽  
Biologically Relevant ◽  
Sensing Platform ◽  
Order Of Magnitude

The detection, manipulation, and tracking of magnetic nanoparticles is of major importance in the fields of biology, biotechnology, and biomedical applications as labels as well as in drug delivery, (bio-)detection, and tissue engineering. In this regard, the trend goes towards improvements of existing state-of-the-art methodologies in the spirit of timesaving, high-throughput analysis at ultra-low volumes. Here, microfluidics offers vast advantages to address these requirements, as it deals with the control and manipulation of liquids in confined microchannels. This conjunction of microfluidics and magnetism, namely micro-magnetofluidics, is a dynamic research field, which requires novel sensor solutions to boost the detection limit of tiny quantities of magnetized objects. We present a sensing strategy relying on planar Hall effect (PHE) sensors in droplet-based micro-magnetofluidics for the detection of a multiphase liquid flow, i.e., superparamagnetic aqueous droplets in an oil carrier phase. The high resolution of the sensor allows the detection of nanoliter-sized superparamagnetic droplets with a concentration of 0.58 mg cm−3, even when they are only biased in a geomagnetic field. The limit of detection can be boosted another order of magnitude, reaching 0.04 mg cm−³ (1.4 million particles in a single 100 nL droplet) when a magnetic field of 5 mT is applied to bias the droplets. With this performance, our sensing platform outperforms the state-of-the-art solutions in droplet-based micro-magnetofluidics by a factor of 100. This allows us to detect ferrofluid droplets in clinically and biologically relevant concentrations, and even in lower concentrations, without the need of externally applied magnetic fields.

scholarly journals Cation Sensing Capabilities of A Nitrophenyl Cinnamaldehyde Derivative

Molekul ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 191
Author(s):  
Venty Suryanti ◽  
Fajar Rakhman Wibowo ◽  
Ahmad Marzuki ◽  
Meiyanti Ratna Kumala Sari
Keyword(s):  
Charge Transfer ◽  
Organic Compound ◽  
Charge Density ◽  
Absorption Spectra ◽  
Color Change ◽  
Metal Cations ◽  
Colorimetric Sensing ◽  
Color Changes ◽  
Ligand Charge Transfer ◽  
Cation Sensing

The cationic chemosensor based on organic compound bearing an aminophenol moiety as a receptor for metal analyte and a cinnamaldehyde moiety as chromophoric fragment has been developed. In this work, we report the colorimetric sensing of nitrophenyl cinnamaldehyde derivative, namely methyl-3-(2-hidroxy-5-nitrophenyl amino)-3-phenylpropanoate, towards a variety of metal cations, such as Cu2+, Fe3+, Ni2+ and Zn2+. The cation sensing abilities of the sensor were observed for Cu2+and Fe3+ with a color change from colorless to pink and faint yellow, respectively, The characteristic UV-Vis spectra changes were observed upon addition of Cu2+and Fe3+ cations. The hypsochromic absorption spectra shifts were obtained, indicating the cations and sensor complexations had formed. A metal-to-ligand-charge-transfer (MLCT) had occurred and the charge density of the sensor changed resulting in appearance of new absorption peaks in the UV-Vis spectra and color changes of the sensor solution upon addition of the Cu2+and Fe3+.  

Quantitative detection of near-infrared (NIR) light using organic layered composites

2019 ◽  
Vol 7 (14) ◽  
pp. 4089-4095 ◽  
Author(s):  
Machi Takeuchi ◽  
Hisato Kawashima ◽  
Hiroaki Imai ◽  
Syuji Fujii ◽  
Yuya Oaki
Keyword(s):  
Near Infrared ◽  
Color Change ◽  
Quantitative Detection ◽  
Layered Composites ◽  
Temperature Responsive ◽  
Nir Light

A paper-based device for the quantitative detection of NIR is developed by a combination of polydiacetylene (PDA) and polypyrrole (PPy) with temperature-responsive color-change and photothermal properties, respectively.

scholarly journals Ethylene Glycol Functionalized Gadolinium Oxide Nanoparticles as a Potential Electrochemical Sensing Platform for Hydrazine and p-Nitrophenol

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 633 ◽  
Author(s):  
Chaudhary ◽  
Kumar ◽  
Kumar ◽  
Chaudhary ◽  
Mehta ◽  
...  
Keyword(s):  
Detection Limit ◽  
Ethylene Glycol ◽  
Environmental Pollutants ◽  
Gadolinium Oxide ◽  
Linear Range ◽  
Electrochemical Sensing ◽  
Oxide Nanoparticles ◽  
Sensing Platform ◽  
Gd2o3 Nanoparticles ◽  
Gadolinium Oxide Nanoparticles

The current work reports the successful synthesis of ethylene glycol functionalized gadolinium oxide nanoparticles (Gd2O3 Nps) as a proficient electrocatalytic material for the detection of hydrazine and p-nitrophenol. A facile hydrothermal approach was used for the controlled growth of Gd2O3 Nps in the presence of ethylene glycol (EG) as a structure-controlling and hydrophilic coating source. The prepared material was characterized by several techniques in order to examine the structural, morphological, optical, photoluminescence, and sensing properties. The thermal stability, resistance toward corrosion, and decreased tendency toward photobleaching made Gd2O3 nanoparticles a good candidate for the electrochemical sensing of p-nitrophenol and hydrazine by using cyclic voltammetric (CV) and amperometric methods at a neutral pH range. The modified electrode possesses a linear range of 1 to 10 µM with a low detection limit of 1.527 and 0.704 µM for p-nitrophenol and hydrazine, respectively. The sensitivity, selectivity, repeatability, recyclability, linear range, detection limit, and applicability in real water samples made Gd2O3 Nps a favorable nanomaterial for the rapid and effectual scrutiny of harmful environmental pollutants.

scholarly journals Acoustofluidic Micromixing Enabled Hybrid Integrated Colorimetric Sensing, for Rapid Point-of-Care Measurement of Salivary Potassium

Biosensors ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 73 ◽  
Author(s):  
Vikram Surendran ◽  
Thomas Chiulli ◽  
Swetha Manoharan ◽  
Stephen Knisley ◽  
Muthukumaran Packirisamy ◽  
...  
Keyword(s):  
Color Change ◽  
Point Of Care ◽  
Sample Volume ◽  
Point Of Care Testing ◽  
Colorimetric Sensing ◽  
In Situ Tests ◽  
Detection Scheme ◽  
Chip Technology ◽  
Whole Saliva ◽  
Microfluidic Biosensor

The integration of microfluidics with advanced biosensor technologies offers tremendous advantages such as smaller sample volume requirement and precise handling of samples and reagents, for developing affordable point-of-care testing methodologies that could be used in hospitals for monitoring patients. However, the success and popularity of point-of-care diagnosis lies with the generation of instantaneous and reliable results through in situ tests conducted in a painless, non-invasive manner. This work presents the development of a simple, hybrid integrated optical microfluidic biosensor for rapid detection of analytes in test samples. The proposed biosensor works on the principle of colorimetric optical absorption, wherein samples mixed with suitable chromogenic substrates induce a color change dependent upon the analyte concentration that could then be detected by the absorbance of light in its path length. This optical detection scheme has been hybrid integrated with an acoustofluidic micromixing unit to enable uniform mixing of fluids within the device. As a proof-of-concept, we have demonstrated the real-time application of our biosensor format for the detection of potassium in whole saliva samples. The results show that our lab-on-a-chip technology could provide a useful strategy in biomedical diagnoses for rapid analyte detection towards clinical point-of-care testing applications.

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