A Fluorescent Molecularly Imprinted Polymer-Coated Paper Sensor for On-Site and Rapid Detection of Glyphosate.

Due to the massive use and abuse of pesticides, practices which have led to serious threats to human health, the research community must develop on-site and rapid detection technology of pesticide residues to ensure food safety. Here, a paper-based fluorescent sensor, integrated with molecularly imprinted polymer (MIP) targeting glyphosate, was prepared by a surface-imprinting strategy. The MIP was synthesized by a catalyst-free imprinting polymerization technique and exhibited highly selective recognition capability for glyphosate. The MIP-coated paper sensor not only remained selective, but also displayed a limit of detection of 0.29 µmol and a linear detection range from 0.5 to 10 µmol. Moreover, the detection time only took about 5 min, which is beneficial for rapid detection of glyphosate in food samples. The detection accuracy of such paper sensor was good, with a spiked recovery rate of 92-117% in real samples. The fluorescent MIP-coated paper sensor not only has good specificity, which is helpful to reduce the food matrix interference and shorten the sample pretreatment time, but it also has the merits of high stability, low-cost and ease of operation and carrying, displaying great potential for application in the on-site and rapid detection of glyphosate for food safety.

Urimem facilitates kidney disease biomarker research.

Urine is a body fluid that can be noninvasively acquired and contains important biological information about the patient. Urinary proteins are considered to be the best resource of potential biomarkers for kidney disorders. Urinary proteins can be adsorbed to polyvinylidene fluoride (PVDF) or nitrocellulose membranes, which can then be dried and stored in vacuum bag. This membrane is named Urimem. The membrane can even be stored at room temperature for at least weeks without changing the quantity of eluted proteins. With this simple and inexpensive urimem, it is possible to begin preserving urine sample from all consenting patients during each stage of kidney disease development. Thus, the medical research can be conducted more economically, ultimately benefiting the patients who provided the samples. This can potentially change the landscape of medical research and medical practice.

Occurrence of phthalate esters in over-the-counter medicines from China and its implications for human exposure.

Food, air, personal care products and indoor dust have been recognized as the main routes of exposure to phthalates in Chinese population, but other sources may have been overlooked, e.g., medicines. To fill the knowledge gap, phthalate esters were measured in 96 over-the-counter medicines made in China, including selected 71 Chinese patented medicines and 25 western medicines. It was found that none of the medicines was free of phthalates. The mean concentrations of individual phthalates ranged from 0.001µg/g (dicyclohexyl phthalate) to 5.85µg/g (diethyl phthalate). Among 9 targeted phthalates, di-n-butyl phthalate was the dominant congener, accounting for >65% of the total phthalates in all medicine samples, followed by di-(2-ethylhexyl) phthalate and diethyl phthalate. Phthalates in medicines appeared to derive from gastroresistant film coatings, plastic packing materials or phthalate contaminated rural herbal plants (especially for Chinese patented medicines). Daily human exposure to phthalates was estimated for local patients for one treatment cycle (e.g., one week) based on suggested consumption dosage and phthalate concentrations. Almost all exposure levels were below the guidelines suggested by the United States Environmental Protection Agency or European Food Safety Authority, indicating low health risk with phthalates from consumption of the medicines. In addition, concentration levels of phthalates in patients would increase upon administration but are expected to decrease to the same values as those in patients before they took medicines in several days. Because the number of medicine samples was limited and the concentrations of phthalates varied in a large range, further investigations are needed to acquire more data for better assessment of human health effects for Chinese population. Capsule: Distribution of phthalate esters in over-the-counter medicines and related exposure for Chinese population are examined.

[Comparison of two urinary protein preparation methods: nitrocellulose membrane preservation and acetone precipitation].

Nitrocellulose membrane based urinary protein preservation method is simple, fast and economic, but its advantage over the traditionally used acetone precipitation method is still unclear. In this work, we prepared urinary proteins by the two methods by LC-MS/MS. Then we used protein spectra counts to assess the reproducibility of the two methods. Proteins identified by the two methods were almost the same in number, spectral count distribution and distribution of coefficients of variation value. In conclusion, nitrocellulose membrane method is generally the same as acetone precipitation method. It can be used for large scale preservation of clinical urine samples.

Urimem, a membrane that can store urinary proteins simply and economically, makes the large-scale storage of clinical samples possible.

By nature, biomarker is the measurable change associated with a physiological or pathophysiological process. Unlike blood which has mechanisms to minimize changes and to keep the internal environment homeostatic, urine is more likely to reflect changes of the body and is a better biomarker source. Because of its potential in biomarker discovery, urinary proteins should be preserved comprehensively as the duration of the patients' corresponding medical records. Here, we propose a method to adsorb urinary proteins onto a membrane we named Urimem. This simple and inexpensive method requires minimal sample handling, uses no organic solvents, and is environmentally friendly. Urine samples were filtered through the membrane, and urinary proteins were adsorbed onto the membrane. The proteins on the membrane were dried and stored in a vacuum bag, which keeps the protein pattern faithfully preserved. The membrane may even permit storage at room temperature for weeks. Using this simple and inexpensive method, it is possible to begin preserving urine samples from all consenting people. Thus, medical research especially biomarker research can be conducted more economically. Even more objective large-scale prospective studies will be possible. This method has the potential to change the landscape of medical research and medical practice.

[Comparison of cost-effectiveness between Urimem and direct freezing for urinary protein preservation].

To compare two enrichment and preservation methods of urinary proteins, stored in polyvinylidene difluoride (PVDF) membrane (Urimem) or direct freezing, we examined the differences between the two methods in time, space, costs of supplies and electricity, degree of protein degradation and convenience of the sample handling. The urimem method is superior in the storage space, the cost of electricity and the clinical convenience compared to the direct freezing method. However, the direct freezing method is superior in the time and the cost of supplies to the urimem method. The enrichment and preservation of urinary proteins using urimem have more cost-effective benefits compared to those of the direct freezing method.