A new protocol for fabrication of glass microchips is addressed in this research paper. Initially, the method involves the use of an uncured SU-8 intermediate to seal two glass slides irreversibly as in conventional adhesive bonding-based approaches. Subsequently, an additional step removes the adhesive layer from the channels. This step relies on a selective development to remove the SU-8 only inside the microchannel, generating glass-like surface properties as demonstrated by specific tests. Named sacrificial adhesive layer (SAB), the protocol meets the requirements of an ideal microfabrication technique such as throughput, relatively low cost, feasibility for ultra large-scale integration (ULSI), and high adhesion strength, supporting pressures on the order of 5 MPa. Furthermore, SAB eliminates the use of high temperature, pressure, or potential, enabling the deposition of thin films for electrical or electrochemical experiments. Finally, the SAB protocol is an improvement on SU-8-based bondings described in the literature. Aspects such as substrate/resist adherence, formation of bubbles, and thermal stress were effectively solved by using simple and inexpensive alternatives.

This study presents an inexpensive and easy way to produce a microfluidic device that mimics a blood vessel, serving as a start point for cell culture under perfusion, cardiovascular research, and toxicological studies. Endpoint assays (i.e., MTT reduction and NO assays) were used and revealed that the components making up the microchip, which is made of polyester and toner (PT), did not induce cell death or nitric oxide (NO) production. Applying oxygen plasma and fibronectin improved the adhesion and proliferation endothelial cell along the microchannel. As expected, these treatments showed an increase in vascular endothelial growth factor (VEGF-A) concentration profiles, which is correlated with adherence and cell proliferation, thus promoting endothelialization of the device for neovascularization. Regardless the simplicity of the device, our “vein-on-a-chip” mimetic has a potential to serve as a powerful tool for those that demand a rapid microfabrication method in cell biology or organ-on-a-chip research.

Glass/SU-8 microchip for electrokinetic applicationsIn this communication, we describe the fabrication and electric characterization of a hybrid glass/SU-8 microchannels for high-performance electrokinetic applications. The bonding process employed SU-8 film as intermediate layer with reduced baking times; all the procedure took less than 50 min (only about 10 min disregarding the cleaning and dehydration steps). Additionally, further steps to improve the adhesion of the substrate to the SU-8 were not needed. The developed configuration aggregates the advantages of both substrates, including (i) simple fabrication techniques; (ii) high compatibility for integration of microelectromechanical, optical, and electrochemical components (SU-8); (iii) high and stable electroosmotic mobility ( EO ); and (iv) satisfactory heat dissipation capacity (glass). Electroosmotic mobilities were measured as a function of the pH using the current monitoring method, whereas the heat dissipation capacity was investigated through Ohm's law plots for both glass and glass/SU-8 microchips. The measured EO values were similar for both microdevices, with mobilities of the order of 4.0-4.5 × 10 −4 cm 2 V −1 cm −1 at 4-12 pH range using phosphate buffer (10 and 20 mmol/L). The heat dissipation assays were carried out in microchannels filled with 20 mmol/L phosphate buffer. A considerable Joule heating was observed only at electric field strengths greater than 580 V cm −1 in hybrid glass/SU-8 microdevices, representing a substantial increase of 48% when compared to all SU-8 microdevices. Keywords:Bonding / Microfabrication / Photoresist DOI 10.1002/elps.201300167Additional supporting information may be found in the online version of this article at the publisher's web-siteMicrodevices integrating CE are a potential platform for microfluidics applications, especially for biomolecular assays in proteomics and metabolomics research. This platform provides simple, effective, small-in-volume, and high-resolution separations. Glass is the most used material in the fabrication of CE chips [1]. Vitreous substrates carry important advantages, including (i) optical transparency, (ii) chemical inertia, (iii) high and stable electroosmotic mobility ( EO ), and (iv) good thermal conductivity ( = 1.5 W mK −1 ) [2]. The latter allows the application of high electric field strengths (>600 V cm −1 ) without formation of temperature gradienta negligible Joule heating, contributing for fast separations.

Sarcosine is an amino acid that has been listed as a new indicator for prostate cancer.

Composting is a sustainable approach to manage animal and vegetal waste generated in the Fundação Parque Zoológico de São Paulo. The resulting compost is often used in ZOO's premises as an organic fertilizer for the production of vegetables, which is further used to feed the animals. The composting product provides many forms of mineral and also amino acids (AA) that are absorbed by plants as nutrients. Since most amino acids absorb only slightly or not at all in the UV wavelengths, we developed a method for the determination of AA of agricultural interest in the composting samples. Due to the complexity of samples, we used ion exchange chromatography for the purification of AA prior to analysis. The proposed CZE-C D method allowed a separation of the AA in a short analysis time (less than 3.0 min), with great linearity (with R ranging from 0.993 to 0.998). Using a BGE of 10 mmol/L TEA, reduction of high-frequency noise and lower baseline fluctuations were obtained. The LOQ for the five AA were around 35 μmol/L, and were adequate for our purpose. In addition, the method showed good precision (RSD of peak area and migration time less than 1.55 and 1.16%, respectively).

Electrophoresis 2016, 37, 2449–2457. DOI: If an average household produces weekly several pounds of organic garbage, imagine the volume of a large zoo like São Paulo Zoo. The amount of organic waste, from feeding left overs, to plants, manure and even dead animals, is enough to produce up to 120 tons monthly. If all this organic matter was sent to dumping grounds, this would create a serious environmental problem. Composting is a sustainable approach by the São Paulo Zoo to manage animal and vegetal waste generated in the Zoo's premises. The resulting compost is often used as organic fertiliser for the production of vegetables, which is further used to feed the animals. The compost produced provides many forms of minerals and also amino acids (AA) that are used by plants as nutrients. Since most amino acids absorb only slightly or not at all in the UV wavelengths, we developed a method for the determination of AA of agricultural interest in the compost samples. Due to the complexity of these samples, we used ion exchange chromatography for purification of AA prior analysis. The proposed CZE‐C4Dmethod allowed a separation of the AA in a short analysis time (less than 3.0 min) without the need for derivatization, with sensitivity and reproducibility suitable for such samples. Photograph: Paulo Gil