Determination Of Clenbuterol And Methamphetamine Based On Glass Microfluidic Chip

The traditional methods for the determination of small molecules in the body are high performance liquid chromatography, gas chromatography, high performance liquid chromatography-mass spectrometry. But the process of the pretreatment is always complex and time-consuming, the tedious, cumbersome equipment makes analysis only possible in the central lab. Microfluidic chip technology is a new platform on analysis. It needs less sample consumption and makes the detection faster and high-throughput. This study took the clenbuterol and methamphetamine as the examples, combined Surface-enhanced Raman Spectroscopy (SERS) to develop two kinds of microfluidic platforms on small molecules detection, showed the huge potential application microfluidic chip in the field of small molecules detection.Clenbuterol hydrochloride is an illegal but widely-used feed additive, it can increase the lean meat content, but will produce a series of side effects to the human body. Detecting the clenbuterol hydrochloride in swine hair is an effective supervision of irregularities. This study developed a competitive immunoassay to determine the clenbuterol hydrochloride in the swine hair extract at femtogram level, which integrated the power of magnetic nanoparticles, microfluidics and surface-enhanced Raman spectroscopy (SERS). In the main microchannel, magnetic nanoparticles on which the clenbuterol hydrochloride monoclonal antibodies were immobilized were mixed and reacted with the swine hair extract doped with gold nanoparticles labelled with Raman reporter (4-Mercaptobenzoic acid) and clenbuterol standard. The magnetic immunocomplex produced in the reaction was then immoblized and enriched in the downstream microchannel by a magnet for Raman detection. A washing microchannel was designed to remove the interference of fluorescent species in the swine hair extract. The immunoassay was accomplished in minutes due to chaotic mixing in the microchannel. The total analytical time was reduced to about 1 hour. This method allows on-site fast analysis of clenbuterol hydrochloride in the swine hair extract with high specificity and sensitivity.Methamphetamine, commonly known as crystal meth, is a kind of stimulant drugs with severe toxicity. The common analytical technique used by the public security departments are strip test and high performance liquid chromatography (HPLC). Strip tests may appear false positive results, so the high performance liquid chromatography usually comes after the strip tests for the accurate results. We developed a fast detection of methamphetamine in plasma samples based on Surface-enhanced Raman Spectroscopy (SERS) and glass microfluidic chip. The samples, salts and nanoparticles flew into the micro channel with the help of an injection pump at the outlet. Raman signals could be detected in only 3-5 minutes. This method not only can be used to detect the plasma samples, but also for the detection of urine and saliva samples. When the device is combined with the portable Raman instruments, it is expected to become a new detection method for public security department.