An affordable 3D-printed positioner fixture improves the resolution of conventional milling for easy prototyping of acrylic microfluidic devices

Guevara-Pantoja, Pablo E.; Chavez-Pineda, Oriana Gerallin; Solís-Serrano, Alberto Missael; García-Cordero, José L.; Caballero‐Robledo, Gabriel A.

doi:10.1039/d0lc00549e

Cited by 7 publications

(7 citation statements)

References 31 publications

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“…The mold was placed in a petri dish with 3 mL of chloroform for 5 min in order to eliminate any roughness on the structures caused by the milling process. [ 56 ] Devices were fabricated by pouring polydimethylsiloxane (PDMS, Sylgard 184, Corning) on the mold at a 10:1 base to curing agent ratio (w/w). The devices were cured for 40 min at 80 °C in a convection oven.…”

Section: Methodsmentioning

confidence: 99%

Hybrid Opto‐Thermocycler for RT‐qPCR Detects SARS‐CoV‐2

Guevara-Pantoja

Rodriguez‐Moncayo

Chavez-Pineda

et al. 2022

Adv Materials Technologies

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Although real‐time quantitative reverse transcription polymerase chain reaction (RT‐qPCR) is the gold standard for detecting the virus severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) and other pathogens, the coronavirus disease 2019 (COVID‐19) pandemic has highlighted the scarcity of instruments, devices, and reagents for polymerase chain reaction (PCR) testing in constrained settings. At least for under‐resourced countries, it has become critical to deploy instruments that can be rapidly constructed and satisfy this demand. Instead of separating the optical system from the thermal module (typical of qPCR thermocyclers), we report a portable Hybrid Opto‐Thermocycler—dubbed HybOT Cycler—that takes advantage of the high‐temperature tolerances (>100 °C) of electronic and optical components to combine thermal control, illumination, and fluorescence detection into a highly integrated hybrid module. This simple configuration allowed us to reduce the overall number of components, thus simplifying its assembly and reducing the instrument size. The HybOT Cycler is wirelessly controlled from an application installed in a tablet. PCR assays are carried out in a bubble‐free microfluidic device that can be easily replicated from an acrylic mold. Using the HybOT Cycler, down to 100 copies/µL of genetic material of the virus SARS‐CoV‐2 with 95% sensitivity and 100% specificity is detected. The HybOT Cycler can assist in diagnosing SARS‐CoV‐2 and other pathogens in resource‐poor settings.

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Section: Methodsmentioning

confidence: 99%

Hybrid Opto‐Thermocycler for RT‐qPCR Detects SARS‐CoV‐2

Guevara-Pantoja

Rodriguez‐Moncayo

Chavez-Pineda

et al. 2022

Adv Materials Technologies

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“…To solve this problem, a piezoelectric actuator was fabricated and coupled to the milling machine, which allowed the manipulation of the vertical axis with high precision. [27][28][29] The device geometry allows for the introduction of the microparticles through input (a) in Fig. 1(A) to fill the three chambers just above the restrictions (d) shown in Fig.…”

Section: A Microfabricationmentioning

confidence: 99%

Micro–nanoparticles magnetic trap: Toward high sensitivity and rapid microfluidic continuous flow enzyme immunoassay

2020

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In this work, we developed a microfluidic system for immunoassays where we combined the use of magnetic nanoparticles as immunosupport, a microfluidic magnetic trap, and a fluorogenic substrate in continuous flow for detection which, together with the optimization of the functionalization of surfaces to minimize nonspecific interactions, resulted in a detection limit in the order of femtomolar and a total assay time of 40 min for antibiotin antibody detection. A magnetic trap made of carbonyl-iron microparticles packaged inside a 200 μm square microchannel was used to immobilize and concentrate nanoparticles. We functionalized the surface of the iron microparticles with a silicapolyethylene glycol (PEG) shell to avoid corrosion and unspecific protein binding. A new one-step method was developed to coat acrylic microchannels with an organofunctional silane functionalized with PEG to minimize unspecific binding. A model immunoassay was performed using nanoparticles decorated with biotin to capture antibiotin rabbit Immunoglobulin G (IgG) as target primary antibody. The detection was made using antirabbit IgG labeled with the enzyme alkaline phosphatase as a secondary antibody, and we measured fluorescence with a fluorescence microscope. All steps of the immunoassay were performed inside the chip. A calibration curve was obtained in which a detection limit of 8 pg/ml of antibiotin antibody was quantified. The simplicity of the device and the fact that it is made of acrylic, which is compatible with mass production, make it ideal for Point-Of-Care applications.

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“…5,6 Thermoplastic materials have gained significant popularity for microfluidic applications 1,7 because they can be manufactured in large volumes at low cost by employing a set of replication and direct fabrication techniques, such as injection and compression molding, hot embossing, microthermoforming, casting, micro-milling, laser ablation, plasma etching and 3D printing. [8][9][10][11][12][13] Thermoplastics are economical, relatively resistant to chemicals, have excellent optical transparency, and possess different mechanical properties. Cyclic olefin copolymer (COC), polycarbonate (PC), poly (methyl methacrylate) (PMMA), polystyrene (PS), polyethylene terephthalate (PET), polypropylene (PP), and polyvinyl chloride (PVC), among others, 7,14,15 are some of the most common thermoplastics used in industry and also to manufacture microfluidic devices.…”

Section: Introductionmentioning

confidence: 99%