Detection of aldehydes by gold nanoparticles colorimetric array based on Tollens’ reagent

2021 ◽  
Author(s):  
Qinghai Zhang ◽  
Jiawei Li ◽  
You Wang ◽  
Yi Ma ◽  
Miao He ◽  
...  

Aldehydes are the most common pollutants and the most possible human carcinogens in human life. Herein, we reported an easy-to-operate and low-cost method for discrimination of diverse aldehydes. One new...

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 697
Author(s):  
Siming Lu ◽  
Sha Lin ◽  
Hongrui Zhang ◽  
Liguo Liang ◽  
Shien Shen

Respiratory viral infections threaten human life and inflict an enormous healthcare burden worldwide. Frequent monitoring of viral antibodies and viral load can effectively help to control the spread of the virus and make timely interventions. However, current methods for detecting viral load require dedicated personnel and are time-consuming. Additionally, COVID-19 detection is generally relied on an automated PCR analyzer, which is highly instrument-dependent and expensive. As such, emerging technologies in the development of respiratory viral load assays for point-of-care (POC) testing are urgently needed for viral screening. Recent advances in loop-mediated isothermal amplification (LAMP), biosensors, nanotechnology-based paper strips and microfluidics offer new strategies to develop a rapid, low-cost, and user-friendly respiratory viral monitoring platform. In this review, we summarized the traditional methods in respiratory virus detection and present the state-of-art technologies in the monitoring of respiratory virus at POC.


2015 ◽  
Vol 69 (1) ◽  
Author(s):  
Jana Šefčovičová ◽  
Jan Tkac

AbstractMicrobial cell biosensors, where cells are in direct connection with a transducer enabling quantitative and qualitative detection of an analyte, are very promising analytical tools applied mainly for assays in the environmental field, food industry or biomedicine. Microbial cell biosensors are an excellent alternative to conventional analytical methods due to their specificity, rapid detection and low cost of analysis. Nowadays, nanomaterials are often used in the construction of biosensors to improve their sensitivity and stability. In this review, the combination of microbial and other individual cells with different nanomaterials (carbon nanotubes, graphene, gold nanoparticles, etc.) for the construction of biosensors is described and their applications are provided as well.


Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 347
Author(s):  
Beomjin Kim ◽  
Woo Chang Song ◽  
Sun Young Park ◽  
Geuntae Park

The green synthesis of inorganic nanoparticles (NPs) using bio-materials has attained enormous attention in recent years due to its simple, eco-friendly, low-cost and non-toxic nature. In this work, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized by the marine algae extract, Sargassum serratifolium (SS). The characteristic studies of bio-synthesized SS-AgNPs and SS-AuNPs were carried out by using ultraviolet–visible (UV–Vis) absorption spectroscopy, dynamic light scattering (DLS), high-resolution transmission electron microscope (HR-TEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Phytochemicals in the algae extract, such as meroterpenoids, acted as a capping agent for the NPs’ growth. The synthesized Ag and Au NPs were found to have important catalytic activity for the degradation of organic dyes, including methylene blue, rhodamine B and methyl orange. The reduction of dyes by SS-AgNPs and -AuNPs followed the pseudo-first order kinetics.


Author(s):  
V. Annapoorani ◽  
P. Rathna ◽  
C. Priyanka ◽  
B. Maheshwari ◽  
E. Leela

The paper reports an Internet of Thing (IoT) based health monitoring and tracking system for soldiers. The proposed system can be mounted on the soldier’s body to track their health status and current location using GPS. These information will be transmitted to the control room through IoT. The proposed system comprise of tiny wearable physiological equipment’s, sensors, transmission modules. Hence, with the use of the proposed equipment, it is possible to implement a low cost mechanism to protect the valuable human life on the battlefield


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Kristina Gudun ◽  
Zarina Elemessova ◽  
Laura Khamkhash ◽  
Ekaterina Ralchenko ◽  
Rostislav Bukasov

We introduce low-cost, tunable, hybrid SERS substrate of commercial gold nanoparticles on untreated aluminum foil (AuNPs@AlF). Two or three AuNP centrifugation/resuspension cycles are proven to be critical in the assay preparation. The limits of detection (LODs) for 4-nitrobenzenethiol (NBT) and crystal violet (CV) on this substrate are about 0.12 nM and 0.19 nM, respectively, while maximum analytical SERS enhancement factors (AEFs) are about 107. In comparative assays LODs for CV measured on AuNPs@Au film and AuNPs@glass are about 0.35 nM and 2 nM, respectively. The LOD for melamine detected on AuNPs@ Al foil is 27 ppb with 3 orders of magnitude for linear response range. Overall, AuNPs@AlF demonstrated competitive performance in comparison with AuNPs@ Au film substrate in SERS detection of CV, NBT, and melamine. To check the versatility of the AuNPs@AlF substrate we also detected KNO3 with LODs of 0.7 mM and SERS EF around 2 × 103, which is on the same order with SERS EF reported for this compound in the literature.


The Analyst ◽  
2019 ◽  
Vol 144 (4) ◽  
pp. 1205-1209 ◽  
Author(s):  
Chi Zhang ◽  
Caiyun Kong ◽  
Qingyun Liu ◽  
Zhengbo Chen

We herein present a simple, low-cost, and ultrasensitive colorimetric sensing strategy for the detection of mercury ions (Hg2+) that takes advantage of the natural pore structure in rose petals to encapsulate gold nanoparticles (AuNPs).


2020 ◽  
Vol 20 (6) ◽  
pp. 3356-3360
Author(s):  
Hao Yong Yin ◽  
Yi Fan Zheng ◽  
Ling Wang

We report the formation of gold nanoparticles on indium tin oxide conducting glass (ITO) surface via electrodeposition method at room temperature. The prepared nano-Au electrodes has been fabricated for sensitive detection of Pb2+, and showed highly selective response toward Pb2+. The electrochemical detection of Pb2+ were determined by differential pulse stripping voltammetric (DPSV). The nano-Au electrochemical sensor could detect Pb2+ from 0.5 to 10 μM with detection limits of 0.06 μM (S/N= 3) and sensitivity of 0.27996 mA μM−1. The proposed sensor is simple, reliable, sensitive, selective, and low-cost, thus holds potential for practical application in Pb2+ detection.


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