News

Mar 2012
Pittcon 2012

Nanova representatives will attend Pittcon 2012 at the Orange County Convention Center, Orlando, FL, USA.

Feb 2012
Detection of Pesticides in Tomatoes and Apples
Researchers at University of Missouri have recently successfully demonstrated detection of pesticides using Q-SERS G1 substrates. Three types of pesticides widely used in apples and tomatoes (carbaryl, phosmet, and azinphos-methyl) were used in the study. Significantly enhanced Raman signals of pesticides were acquired by SERS from the extract of fruit samples and exhibited characteristic patterns of the analytes. Multivariate statistical methods such as partial least squares and principal component analysis were used to develop quantitative and qualitative models. Q-SERS G1 was able to detect all three types of pesticides extracted from fruit samples at the parts per million level. The study of detection limit demonstrated that at 99.86% confidence interval, Q-SERS G1 can detect carbaryl at 4.51 ppm, phosmet at 6.51 ppm, and azinphos-methyl at 6.66 ppm spiked on apples; and carbaryl at 5.35 ppm, phosmet at 2.91 ppm, and azinphos-methyl at 2.94 ppm on tomatoes. Most of these detection limits meet the maximum residue limits established by Food and Agriculture Organization of the United Nations and World Health Organization. Satisfactory recoveries (78–124%) were achieved for samples with concentrations at and larger than the detection limit. These results demonstrate that Raman coupled with Q-SERS G1 substrates is a rapid, sensitive, and reliable method for detection and characterization of chemical contaminants in foods. More information could be found in the following publication:

“Detection of Pesticides in Fruits by Surface-Enhanced Raman Spectroscopy Coupled with Gold Nanostructures,” Bin Liu et. al., Food and Bioprocess Technology, 2012

July 2011
Comparison between G1 and G0
The Q-SERS G1 and G0 (recently launched) have different characteristics that may meet different needs. The water contact angle of G1 is about 130±2º, while the water contact angle of G0 is about 50±2º. The precisely controlled water contact angle are particularly important when a droplet of analyte would be deposited on the substrates for detection. The hydrophobic G1 is very helpful to make more defined and more concentrated droplet residue for ease of detection and for better reproducibility. Attached please find more information on the comparison of G1, G0, and competitors’ products.
Better Controlled Contact Angle Lead to More Repeatable Results
Detection Limit Comparison between G1 and G0

Jan 2011
Detection of an Illegal Anti-Fungal Agent for Fishery Production

Researchers at Shanghai Ocean University and Washington State University studied the application of Q-SERS G1 for detection of crystal violet, an effective anti-fungal agent, often illegally used in fishery production. It is found that the detection limit is around 20 ppb. The data has also been analyzed by Partial least square regression (PLS) and multiple linear regression (MLR). Both PLS and MLR models showed potential for quantitative analysis for crystal violet using Q-SERS G1 data. The R2 of log values of crystal violet concentrations versus their values predicted by PLS or MLR models were about 0.84–0.87. In addition, this paper also compared Q-SERS G1 with a commercial product from one our competitors. More information could be found in the following publication:

“Determination of chloramphenicol and crystal violet with surface enhanced Raman spectroscopy,” Lai et. al., Sens. & Instrumen. Food Qual. (2011) 5:19–24