Nanotechnology enabled platforms for trace detection of pharmaceuticals

Author(s):  
Venkata Praveen Annam ◽  
Timothy O. Mertz ◽  
Krishna Vattipalli ◽  
Vinay Nagaraj ◽  
Shalini Prasad
Keyword(s):  
Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 723
Author(s):  
Kgotla K. Masibi ◽  
Omolola E. Fayemi ◽  
Abolanle S. Adekunle ◽  
Amal M. Al-Mohaimeed ◽  
Asmaa M. Fahim ◽  
...  

This report narrates the successful application of a fabricated novel sensor for the trace detection of endosulfan (EDS). The sensor was made by modifying a glassy-carbon electrode (GCE) with polyaniline (PANI), chemically synthesized antimony oxide nanoparticles (AONPs), acid-functionalized, single-walled carbon nanotubes (fSWCNTs), and finally, the AONP-PANI-SWCNT nanocomposite. The electrochemical properties of the modified electrodes regarding endosulfan detection were investigated via cyclic voltammetry (CV) and square-wave voltammetry. The current response of the electrodes to EDS followed the trend GCE-AONP-PANI-SWCNT (−510 µA) > GCE-PANI (−59 µA) > GCE-AONPs (−11.4 µA) > GCE (−5.52 µA) > GCE-fSWCNTs (−0.168 µA). The obtained results indicated that the current response obtained at the AONP-PANI-SWCNT/GCE was higher with relatively low overpotential compared to those from the other electrodes investigated. This demonstrated the superiority of the AONP-PANI-SWCNT-modified GCE. The AONP-PANI-SWCNT/GCE demonstrated good electrocatalytic activities for the electrochemical reduction of EDS. The results obtained in this study are comparable with those in other reports. The sensitivity, limit of detection (LoD), and limit of quantification (LoQ) of AONP-PANI-SWCNT/GCE towards EDS was estimated to be 0.0623 µA/µM, 6.8 µM, and 20.6 µM, respectively. Selectivity, as well as the practical application of the fabricated sensor, were explored, and the results indicated that the EDS-reduction current was reduced by only 2.0% when interfering species were present, whilst average recoveries of EDS in real samples were above 97%.


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1743
Author(s):  
Qianhui Gu ◽  
Chaoqun Lu ◽  
Kangwen Chen ◽  
Xingguang Chen ◽  
Pengfei Ma ◽  
...  

The rapid quantification of capsaicinoids content is very important for the standardization of pungent taste degree and flavor control of soy sauce and pot-roast meat products. To rapidly quantify the capsaicinoids content in soy sauce and pot-roast meat products, an electrochemical sensor based on β-cyclodextrin/carboxylated multi-wall carbon nanotubes was constructed and the adsorptive stripping voltammetry method was used to enrich samples in this study. The results showed that the excellent performance of the established electrochemical sensor was mostly because β-cyclodextrin caused the relative dispersion of carboxylated multi-wall carbon nanotubes on the glassy carbon electrode surface. Capsaicin and dihydrocapsaicin had similar electrochemical behavior, so the proposed method could determine the total content of capsaicinoids. The linearity of capsaicinoids content was from 0.5 to 100 μmol/L and the detection limit was 0.27 μmol/L. The recovery rates of different capsaicinoids content were between 83.20% and 136.26%, indicating the proposed sensor could realize trace detection of capsaicinoids content in sauce and pot-roast meat products. This work provides a research basis for pungent taste degree standardization and flavor control in the food industry.


2011 ◽  
Vol 699 (2) ◽  
pp. 232-241 ◽  
Author(s):  
Supaporn Dawan ◽  
Proespichaya Kanatharana ◽  
Booncharoen Wongkittisuksa ◽  
Warakorn Limbut ◽  
Apon Numnuam ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Praveen K. Sekhar ◽  
Jie Zhou ◽  
Hui Wang ◽  
Eric R. Hamblin

Selective and sensitive detection of trace amounts of pentaerythritol tetranitrate (PETN) is demonstrated. The screening system is based on a sampling/concentrator front end and electrochemical potentiometric gas sensor as the detector. A single sensor is operated in the dominant hydrocarbon (HC) and nitrogen oxides (NOx) mode by varying the sensor operating condition. The potentiometric sensor with integrated heaters was used to capture the signature of PETN. Quantitative measurements based on hydrocarbon and nitrogen oxide sensor responses indicated that the detector sensitivity scaled proportionally with the mass of the explosives (10 μg down to 200 ng). The ratio of the HC integrated peak area to the NOxintegrated peak area is identified as an indicator of selectivity. The HC/NOxratio is unique for PETN and has a range from 1.7 to 2.7. This detection technique has the potential to become an orthogonal technique to the existing explosive screening technologies for reducing the number of false positives/false negatives in a cost-effective manner.


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