Preparation of a fluorescent silver nanoprism–dye complex for detection of hydrogen peroxide in milk

2015 ◽  
Vol 7 (23) ◽  
pp. 9749-9752 ◽  
Author(s):  
Chifang Peng ◽  
Chunli Liu ◽  
Zhengjun Xie

A simple and sensitive “turn-on” fluorescence detection method for H2O2in milk was developed based on H2O2induced morphology transitions of fluorescent dye–protein complex-capped silver nanoprisms (FDSNPs).

2020 ◽  
Vol 16 ◽  
Author(s):  
Ikko Mikami ◽  
Eri Shibayama ◽  
Kengo Takagi

Background: Determination of a reducing substance based on the reaction between Ce(IV) and a reducing substance and fluorescence detection of Ce(III) generated has been reported as a selective and sensitive method. However, this method could not be applied to the determination of alcohol due to the low reaction rate of alcohol and Ce(IV). Objective: We found that thiosulfate catalytically enhanced reaction of alcohols (such as, methanol, ethanol, and propanol) and Ce(IV). Utilizing this effect, we developed a new method for the determination of alcohols. Results: In the presence of thiosulfate, an increase in fluorescence intensity was detected by injecting alcohol at concentrations of several millimolar, whereas it was not observed even at the concentration of 10% v/v (2 M for ethanol) in the absence of thiosulfate. The optimum detection conditions were determined to be 4.0 mM Ce(IV) sulfate and 0.50 mM thiosulfate, and the detection limit (S/N = 3) of ethanol under these conditions was 1 mM. In the calibration curves, changes in the slope were observed when the alcohol concentrations were approximately 10–25 mM. Using a thiosulfate solution containing ethanol as the reaction solution, a calibration curve without any change in slope was obtained, although the concentration of ethanol at the detection limit increased. The alcohols in the liquor and fuel were successfully analyzed using the proposed detection method as a postcolumn reaction. Conclusion: This new alcohol detection method using a versatile fluorescence detector can be applied to the postcolumn reaction of HPLC omitting need of time-consuming pretreatment processes.


Author(s):  
Wenjie Liu ◽  
Chenchen Yang ◽  
Hongyan Zhang ◽  
Zhanxian Li ◽  
Mingming Yu

2014 ◽  
Vol 97 (2) ◽  
pp. 492-497 ◽  
Author(s):  
Andrew D Turner ◽  
Monika Dhanji-Rapkova ◽  
Clothilde Baker ◽  
Myriam Algoet

Abstract AOAC Official Method 2005.06 precolumn oxidation LC-fluorescence detection method has been used for many years for the detection and quantitation of paralytic shellfish poisoning (PSP) toxins in bivalve molluscs. After extensive single- and multiple-laboratory validation, the method has been slowly gaining acceptance worldwide as a useful and practical tool for official control testing. In Great Britain, the method has become routine since 2008, with no requirement since then for reverting back to the bioassay reference method. Although the method has been refined to be semiautomated, faster, and more reproducible, the quantitation step can be complex and time-consuming. An alternative approach was developed to utilize the qualitative screening results for generatinga semiquantitative results assessment. Data obtained over 5 years enabled the comparison of semiquantitative and fully quantitative PSP results in over 15 000 shellfish samples comprising eight different species showed that the semiquantitative approach resulted in over-estimated paralytic shellfish toxin levels by an average factor close to two in comparison with the fully quantified levels. No temporal trends were observed in the data or relating to species type, with the exception of surf clams. The comparison suggested a semiquantitative threshold of 800 μg saxitoxin (STX) eq/kg should provide a safe limitfor the determination of samples to be forwarded to full quantitation. However, the decision was taken to halve this limit to include an additional safety factor of 2, resulting in the use of a semiquantitative threshold of 400 μg STX eq/kg. Implementation of the semiquantitative method into routine testing would result in a significant reduction in the numbers of samples requiring quantitation and have a positive impact on the overall turnaround of reported PSP results. The refined method would be appropriate for any monitoring laboratory faced with high throughput requirements.


The Analyst ◽  
2016 ◽  
Vol 141 (20) ◽  
pp. 5886-5892 ◽  
Author(s):  
Jing Wang ◽  
Chenxing Jiang ◽  
Xiaoqi Wang ◽  
Ligeng Wang ◽  
Aimin Chen ◽  
...  

A new CdTe@SiO2@CdSe nanohybrid was demonstrated for the ratiometric fluorescence detection of Cd2+via the turn-on model and “ion-imprinting” technique.


Sign in / Sign up

Export Citation Format

Share Document