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Surface-enhanced Raman scattering (SERS) is a powerful tool for constructing biomolecular fingerprints, which play a vital role in differentiation of bacteria. Due to the rather subtle differences in the SERS spectra among different bacteria, artificial intelligence is usually adopted and enormous amounts of spectral data are required to improve the differentiation efficiency. However, in many cases, large volume data acquisition on bacteria is not only technical difficult but labour intensive. It is known that surface modification of SERS nanomaterials can bring additional dimensionality (difference) of the SERS fingerprints. Here in this work, we show that the concept could be used to improve the bacteria differentiation efficiency. Ag NPs were modified with 11-mercaptoundecanoic acid, 11-mercapto-1-undecanol, and 1-dodecanethiol to provide additional dimensionality. The modified NPs then were mixed with cell lysate from different strains of Bacillus cereus (B. cereus). Even by applying a simple PCA process to the resulting SERS spectra data, all the three modified Ag NPs showed superior differentiation results compared with bare Ag NPs, which could only separate Staphylococcus aureus (S. aureus) and B. cereus. It is believed that the multidimensional SERS could find great potential in bacteria differentiation.

Organophosphorus flame retardant (OPFRs) is a new type of environmental pollutant, and the rapid and sensitive detection of OPFRs is a very important job. A new experimental phenomenon was found that TCEP, a kind of organophosphorus flame retardant, can effectively enhance the signal of the luminol-H2 O2 chemiluminescence (CL) system. Combined with the controllability of flow injection analysis, a rapid, stable, and sensitive CL method was established. The CL intensity responded linearly to the concentration of TCEP in the range 0.5 μg/L to 100 μg/L (R2 = 0.999) with a low detection limit of 33 ng/L. The relative standard deviation (R.S.D.) was 2.2 % (n= 7, c= 100 μg/L). The water samples were labeled and recycled with RSDs of 1.1 % - 5.7 % and recoveries of 88.7 % - 116.1 %. Based on this, this study established a new CL detection method for environmental pollutant TCEP.

Tetracycline (TC) represents a broad-spectrum antibiotic to treat bacterial infections. In this study, a ratiometric fluorescence (FL) probe was developed for the detection of TC in water samples by using waste printing paper extract as a FL indicator. In this ratiometric probe, the emission of printing paper extract at 436 nm gradually decreased and the emission of mixed solution at 538 nm significantly increased with the sequential addition of TC upon being excited at 390 nm, coupled with a remarkable FL color change from bright blue to faint yellow. Thus, a ratiometric F538 /F436 FL probe was created for TC detection by simply mixing the printing paper extraction and TC. Under the optimized conditions, the linear range from 1-100 μM and a detection limit of 0.48 μM (S/N = 3) for TC were obtained. Importantly, the FL probe can be easily prepared with rapid response, high sensitivity, and good selectivity. The application of the waste printing paper extract for the detection of TC in environmental water samples was demonstrated.

On-site identification and quantification of chemicals is critical for promoting food safety, human health, homeland security risk assessment, and disease diagnosis. Surface-enhanced Raman spectroscopy (SERS) has been widely considered as a promising method for on-site analysis due to the advantages of nondestructive, abundant molecular information, and outstanding sensitivity. However, SERS for on-site application has been restricted not only by the cost, performance, and portability of portable Raman instruments, but also by the sampling ability and signal enhancing performance of the SERS substrates. In recent years, the performance of SERS for on-site analysis has been improved through portable Raman instruments, SERS substrates, and other combined technologies. In this review, popular commercial portable Raman spectrometers and the related technologies for on-site analysis are compared. In addition, different types of SERS substrates for on-site application are summarized. SERS combined with other technologies, such as electrochemical and microfluidics are also presented. The future perspective of SERS for on-site analysis is also discussed.

A simple, accurate, sensitive and selective fluorescence analysis method for rapid determination of trace amounts of ergometrine maleate has been developed. The method is based on the fluorescence of ergometrine maleate. The calibration graph was linear in the range of 1 × 10−4 to 0.2 µg[sol ]mL and the detection limit was 4 × 10−5 µg[sol ]mL, with a relative standard deviation of 0.32% at 0.05 µg[sol ]mL (n = 11) ergometrine maleate. The influence of foreign compounds was tested. The proposed method was applied successfully to the determination of ergometrine maleate in pharmaceutical preparations and human plasma. Copyright © 2005 John Wiley & Sons, Ltd.