Microreactor technology has shown potential for optimizing synthetic efficiency, particularly in preparing sensitive compounds. We achieved the synthesis of an [ 18 F]fluoride-radiolabeled molecular imaging probe, 2-deoxy-2-[ 18 F]fluoro- d -glucose ([ 18 F]FDG), in an integrated microfluidic device. Five sequential processes—[ 18 F]fluoride concentration, water evaporation, radiofluorination, solvent exchange, and hydrolytic deprotection—proceeded with high radio-chemical yield and purity and with shorter synthesis time relative to conventional automated synthesis. Multiple doses of [ 18 F]FDG for positron emission tomography imaging studies in mice were prepared. These results, which constitute a proof of principle for automated multistep syntheses at the nanogram to microgram scale, could be generalized to a range of radiolabeled substrates.

An improved approach composed of an oxidation reaction in acidic H2O2 solution and a sequential silanization reaction using neat silane reagents for surface modification of poly(dimethylsiloxane) (PDMS) substrates was developed. This solution-phase approach is simple and convenient for some routine analytical applications in chemistry and biology laboratories and is designed for intact PDMS-based microfluidic devices, with no device postassembly required. Using this improved approach, two different functional groups, poly(ethylene glycol) (PEG) and amine (NH2), were introduced onto PDMS surfaces for passivation of nonspecific protein absorption and attachment of biomolecules, respectively. X-ray electron spectroscopy and temporal contact angle experiments were employed to monitor functional group transformation and dynamic characteristics of the PEG-grafted PDMS substrates; fluorescent protein solutions were introduced into the PEG-grafted PDMS microchannels to test their protein repelling characteristics. These analytical data indicate that the PEG-grafted PDMS surfaces exhibit improved short-term surface dynamics and robust long-term stability. The amino-grafted PDMS microchannels are also relatively stable and can be further activated for modifications with peptide, DNA, and protein on the surfaces of microfluidic channels. The resulting biomolecule-grafted PDMS microchannels can be utilized for cell immobilization and incubation, semiquantitative DNA hybridization, and immunoassay.

Three different liquid crystal (LC) perylene diimides were investigated with respect to the optical and physical characteristics of their thin films. Films were prepared by spin-coating, vacuum evaporation, and Langmuir−Blodgett (LB) techniques on substrates such as microscope glass, indium−tin oxide-coated glass and highly oriented pyrolytic graphite. Films were characterized by polarized optical microscopy, absorption and fluorescence emission spectroscopy, and X-ray diffraction. The self-organizing ability of the LC perylene diimides allows them to rapidly reach a stable, low-energy configuration, unlike many thin film materials, and reveals that they are driven to organize and orient in a highly specific fashion, independent of substrate or deposition method. The molecules tend to form a slipped stack arrangement that maximizes attractive π−π electronic interactions, with the π−π stacking axis oriented parallel to the substrate. Relative to the substrate plane, the LC 1 perylene cores are tilted ∼47° along the stacking axis and ∼58° perpendicular to this direction. The two other LCs have similar structures. An analysis of the intermolecular electronic and steric interactions, and of the interactions between the molecules and the substrates, is proposed to explain why this is such a strongly preferred orientation. The implications for the potential use of such molecules in electronic and photovoltaic applications is discussed.

Infectious diseases caused by bacterial pathogens are a worldwide burden. Serious bacterial infection-related complications, such as sepsis, affect over a million people every year with mortality rates ranging from 30% to 50%. Crucial clinical microbiology laboratory responsibilities associated with patient management and treatment include isolating and identifying the causative bacterium and performing antibiotic susceptibility tests (ASTs), which are labor-intensive, complex, imprecise, and slow (taking days, depending on the growth rate of the pathogen). Considering the life-threatening condition of a septic patient and the increasing prevalence of antibiotic-resistant bacteria in hospitals, rapid and automated diagnostic tools are needed. This review summarizes the existing commercial AST methods and discusses some of the promising emerging AST tools that will empower humans to win the evolutionary war between microbial genes and human wits.

Highly efficient capture and enrichment is always the key for rapid analysis of airborne pathogens. Herein we report a simple microfluidic device which is capable of fast and efficient airborne bacteria capture and enrichment. The device was validated with Escherichia coli (E. coli) and Mycobacterium smegmatis. The results showed that the efficiency can reach close to 100% in 9 min. Compared with the traditional sediment method, there is also great improvement with capture limit. In addition, various flow rate and channel lengths have been investigated to obtain the optimized condition. The high capture and enrichment might be due to the chaotic vortex flow created in the microfluidic channel by the staggered herringbone mixer (SHM) structure, which is also confirmed with flow dynamic mimicking. The device is fabricated from polydimethylsiloxane (PDMS), simple, cheap, and disposable, perfect for field application, especially in developing countries with very limited modern instruments.

The challenge of sampling blood from small animals has hampered the realization of quantitative small-animal PET. Difficulties associated with the conventional blood-sampling procedure need to be overcome to facilitate the full use of this technique in mice. Methods: We developed an automated blood-sampling device on an integrated microfluidic platform to withdraw small blood samples from mice. We demonstrate the feasibility of performing quantitative small-animal PET studies using 18 F-FDG and input functions derived from the blood samples taken by the new device. 18 F-FDG kinetics in the mouse brain and myocardial tissues were analyzed. Results: The studies showed that small (;220 nL) blood samples can be taken accurately in volume and precisely in time from the mouse without direct user intervention. The total blood loss in the animal was ,0.5% of the body weight, and radiation exposure to the investigators was minimized. Good model fittings to the brain and the myocardial tissue time-activity curves were obtained when the input functions were derived from the 18 serial blood samples. The R 2 values of the curve fittings are .0.90 using a 18 F-FDG 3-compartment model and .0.99 for Patlak analysis. The 18 F-FDG rate constants K, and k à 4 , obtained for the 4 mouse brains, were comparable. The cerebral glucose metabolic rates obtained from 4 normoglycemic mice were 21.5 6 4.3 mmol/min/100 g (mean 6 SD) under the influence of 1.5% isoflurane. By generating the whole-body parametric images of K à FDG (mL/min/g), the uptake constant of 18 F-FDG, we obtained similar pixel values as those obtained from the conventional regional analysis using tissue time-activity curves. Conclusion: With an automated microfluidic blood-sampling device, our studies showed that quantitative small-animal PET can be performed in mice routinely, reliably, and safely in a small-animal PET facility.

State‐of‐the‐art: Automated chemical reaction circuits have been demonstrated to serve as a miniaturized operation platform for the parallel screening of 32 in situ click chemistry reactions with reduced consumption of reagents. A proof‐of‐concept study was performed with the bovine carbonic anhydrase II (bCAII) click chemistry system.

The SARS-CoV-2 infection that caused the COVID-19 pandemic quickly spread worldwide within two months. Rapid diagnosis of the disease and isolation of patients are effective ways to prevent and control the spread of COVID-19. Therefore, a sensitive immunofluorescent assay method was developed for rapid detection of special IgM and IgG of COVID-19 in human serum within 10 min. The recombinant nucleocapsid protein of 2019 novel coronavirus was used as capture antigen. Lanthanide, Eu(III) fluorescent microsphere, was used to qualitatively/semiquantitatively determine the solid phase immunochromatographic assay. A total of 28 clinical positive and 77 negative serum or plasma samples were included in the test. Based on the analysis of serum or plasma from COVID-19 patients and healthy people, the sensitivity and specificity of the immunochromatographic assay were calculated as 98.72% and 100% (IgG), and 98.68% and 93.10% (IgM), respectively. The results demonstrated that rapid immunoassay has high sensitivity and specificity and was useful for rapid serodiagnosis of COVID-19.