Picomolar melamine enhanced the fluorescence of gold nanoparticles: Spectrofluorimetric determination of melamine in milk and infant formulas using functionalized triazole capped goldnanoparticles

Vasimalai, N.; John, S. Abraham

doi:10.1016/j.bios.2012.10.023

Cited by 66 publications

(21 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…26,27,28 We found that the determination of a particular analyte in the presence of other analytes depends on the type of functional groups present on the surface of AuNPs. For example, 2,5-dimercapto-1,3,4thiadiazole (DMT) capped AuNPs showed extreme selectivity towards Hg(II) even in the presence of 50,000-fold higher concentration of other metal ions 27 whereas 3-amino-5mercapto-1,2,4-triazole (AMTr) capped AuNPs showed selectivity towards melamine 28 . In the present study, 4-amino-6-hydroxy-2-mercaptopyrimidine (AHMP) (Chart S1; ESI (structure B)) capped AuNPs are synthesized and utilized for the selective determination of thiamine in the presence of other vitamin complexes.…”

Section: Ahmp-aunpsmentioning

confidence: 99%

Sensitive and highly selective determination of vitamin B1 in the presence of other vitamin B complexes using functionalized gold nanoparticles as fluorophore

Shankar

John

2015

RSC Adv.

View full text Add to dashboard Cite

The present work describes highly selective and sensitive determination of vitamin B1 (thiamine) using 4-amino-6-hydroxy-2-mercaptopyrimidine capped gold nanoparticles (AHMP-AuNPs) by spectrofluorimetry. The AHMP-AuNPs were synthesized by wet chemical method and were characterized by HR-TEM, XRD, UV-visible, zeta potential and spectrofluorimetry. They show emission maximum at 781 nm while exciting at 520 nm and a large stock shift (261 nm) with a narrow emission profile and good photostability. While adding 0.15 µM thiamine, the red color solution of AHMP-AuNPs changes to purple and the absorbance at 520 was decreased. This is due to the aggregation of AHMP-AuNPs and it was confirmed by HR-TEM. No change in absorbance was observed in the UV-visible spectra for AHMP-AuNPs in the presence of less than micromolar concentration of thiamine. On the other hand, the emission intensity of AHMP-AuNPs was enhanced even in the presence of picomolar concentration of thiamine. Based on the enhancement of emission intensity, the concentration of thiamine was determined. Interestingly, no change in the emission intensity was observed while adding even milli molar concentration of other vitamin B complexes. The present fluorophore showed an extreme selectivity towards the determination of thiamine in the presence of 10,000 fold common interferents including vitamin B2, B3, B6, B9 and vitamin C while the presence of cysteine and glutathionine interferes for the determination of thiamine. A good linearity was observed from 10 to 120 × 10 -12 M thiamine and a detection limit was found to be 6.8 fM/L (S/N = 3). The present method was successfully used for the determination of thiamine in human blood serum samples.of Technology, Trichy, for providing the instrument facility and PSG Institute of Advanced Studies, Coimbatore for HR-TEM measurements. Address

show abstract

Section: Ahmp-aunpsmentioning

confidence: 99%

Sensitive and highly selective determination of vitamin B1 in the presence of other vitamin B complexes using functionalized gold nanoparticles as fluorophore

Shankar

John

2015

RSC Adv.

View full text Add to dashboard Cite

show abstract

“…Based on the European Union regulation on plastics intended to come into contact with foodstuffs (European Union 10/ 2011), melamine is subject to specific migration limit of 2.5 mg kg −1 . Due to the proved toxicity of melamine, the safety limit of melamine ingestion has officially set by the United States Food and Drug Administration (US FDA) as 2.5 μg mL −1 for adult food and 1 μg mL −1 for infant formula [4]. In China, the limitation of melamine migrated from melamine-formaldehyde products was 0.2 mg dm −2 [5].…”

Section: Introductionmentioning

confidence: 99%

Determination of melamine in food contact materials using an electrode modified with gold nanoparticles and reduced graphene oxide

Chen

Cheng

et al. 2015

Microchim Acta

View full text Add to dashboard Cite

We describe an electrochemical sensor for melamine based on a glassy carbon electrode (GCE) modified with reduced graphene oxide that was decorated with gold nanoparticles (AuNP/rGO). The AuNPs/rGO nanocomposite was synthesized by co-reduction of Au(III) and graphene oxide and characterized by transmission electron microscopy, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The response of the modified GCE to melamine was investigated by using hexacyanoferrate as an electrochemical reporter. It is found that the electrochemical response to hexacyanoferrate is increasingly suppressed by increasing concentration of melamine. This is attributed to competitive adsorption of melamine at the AuNP/rGO composite through the interaction between the amino groups of melamine and the AuNPs. The presence of rGO, in turn, provides a platform for a more uniform distribution of the AuNPs and enhances the electron transfer rate of the redox reaction. The findings were used to develop a sensitive method for the determination of melamine. Under optimized conditions, the redox peak current of hexacyanoferrate at a working voltage of 171 mV (vs. SCE) is linearly related to the concentration of melamine in 5.0 to 50 nM range. The method was successfully applied to the determination of melamine in food contact materials.

show abstract

“…Therefore, it is very necessary to monitor the level of MA in milk products to avoid manufacturers adding MA illegally. Nowadays, many methods to determine MA in food samples have been reported, such as high performance liquid chromatography equipped with ultraviolet detector [56], liquid chromatography or gas chromatography coupled with mass spectrometry [7][8][9], fluorescence spectrum [10][11][12] and Raman spectroscopy [13]. All these instrumental analysis methods need complicated sample preparation, and these sample preparation techniques are time-consuming, organic solvent-consuming, and laboursome.…”

Section: Introductionmentioning

confidence: 99%

Determination of melamine in powdered milk by molecularly imprinted stir bar sorptive extraction coupled with HPLC

Luan

Wei

et al. 2015

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

Picomolar melamine enhanced the fluorescence of gold nanoparticles: Spectrofluorimetric determination of melamine in milk and infant formulas using functionalized triazole capped goldnanoparticles

Cited by 66 publications

References 33 publications

Sensitive and highly selective determination of vitamin B1 in the presence of other vitamin B complexes using functionalized gold nanoparticles as fluorophore

Sensitive and highly selective determination of vitamin B1 in the presence of other vitamin B complexes using functionalized gold nanoparticles as fluorophore

Determination of melamine in food contact materials using an electrode modified with gold nanoparticles and reduced graphene oxide

Determination of melamine in powdered milk by molecularly imprinted stir bar sorptive extraction coupled with HPLC

Contact Info

Product

Resources

About