Cell detection is of great significance for biomedical research. Surface enhanced Raman scattering (SERS) has been widely applied to the detection of cells. However, there is still a lack of a general, low-cost, rapid, and sensitive SERS method for cell detection. Herein, a dynamic liquid SERS platform, which combines label-free SERS technique with soft tubular microfluidics for cell detection, is proposed. Compared with common static solid and static liquid measurement, the dynamic liquid SERS platform can present dynamical mixing, precise control of the mixing time, and continuous spectra collection. By characterizing the model molecules, the proposed dynamic liquid SERS platform has successfully demonstrated good stability and repeatability with 1.90% and 4.98% relative standard deviation (RSD), respectively. Three cell lines including one normal breast cell line (MCF-10A) and two breast cancer cell lines (MCF-7 and MDA-MB-231) were investigated in this platform. 270 cell spectra were selected as the training set for the classification of the models based on the K-Nearest Neighbor (K-NN) algorithm. In three independent experiments, three types of cells were identified by a test set containing 180 cell spectra with sensitivities above 83.3% and specificities above 91.6%. The accuracy was 94.1 ± 1.14% among three independent cell identifications. The dynamic liquid SERS platform has shown higher signal intensity, better repeatability, less pretreatment, and obtainment of more spectra with less time consumption. It will be a powerful detection tool in the area of cell research, clinical diagnosis, and food safety.

The enantioselective pyridinylation is important for providing chiral compounds bearing heterocycles of pharmaceutical interests. 4-CN-pyrinde is extensively applied in the radical pyridinylation reaction, however, its’ enantioselective application is highly challenging. To achieve this goal, we propose an electrochemical catalytic activation of 4-CN-pyridine with a chiral transition metal complex instead of direct cathodic reduction. The chiral catalyst acts as the electron mediator and the transition metal catalysis in turn. The radical species from 4-CN-pyridine is captured via radical rebound by chiral catalyst, and undergoes enantioselective pyridinylation reaction. Here, we show the first method for catalytic asymmetric allylic 4-pyridinylation reactions using 4-CN-pyridine under electrochemical conditions.

A “Capillary Force-Driven Stamped” (CFDS) approach is developed for directly printing patterned nanomaterials in aqueous solution, which may be promising for flexible electronics and biomedical analysis.

The chlorination reaction of aromatic compounds is highly important for the synthesis of pharmaceutical products. As the most common chlorination reagent, chlorine is restricted from undergraduate laboratory experiment training due to its toxicity. In this work, we reported the chlorination of aromatic compounds with chlorine generated from the paired electrolysis of N-chlorosuccinimide. The chlorine in this reaction is produced and consumed in an on-demand manner, ensuring the safety of the reaction, workup, and purification. The reaction is evaluated with 5 undergraduate students with reproducible results and conveys the basic concepts of electrochemical organic synthesis and green synthesis to these students.