Fabrication of Hard–Soft Microfluidic Devices Using Hybrid 3D Printing

Widely accessible, inexpensive, easy-to-use consumer 3D printers, such as desktop stereolithography (SLA) and fused-deposition modeling (FDM) systems are increasingly employed in prototyping and customizing miniaturized fluidic systems for diagnostics and research. However, these 3D printers are generally limited to printing parts made of only one material type, which limits the functionality of the microfluidic devices without additional assembly and bonding steps. Moreover, mating of different materials requires good sealing in such microfluidic devices. Here, we report methods to print hybrid structures comprising a hard, rigid component (clear polymethacrylate polymer) printed by a low-cost SLA printer, and where the first printed part is accurately mated and adhered to a second, soft, flexible component (thermoplastic polyurethane elastomer) printed by an FDM printer. The prescribed mounting and alignment of the first-printed SLA-printed hard component, and its pre-treatment and heating during the second FDM step, can produce leak-free bonds at material interfaces. To demonstrate the utility of such hybrid 3D-printing, we prototype and test three components: i) finger-actuated pump, ii) quick-connect fluid coupler, and iii) nucleic acid amplification test device with screw-type twist sealing for sample introduction

Recent Advances in Electrochemiluminescence with Quantum Dots and Arrays of Nanoelectrodes

This review presents the last advances related to analytical and bioanalytical applications of electrochemiluminescence (ECL) achieved by exploiting the special optical or electrochemical properties of quantum dots and nanoelectrodes, respectively. After a brief introduction which covers the basic concepts of ECL detection, the review presents relevant examples dealing with in the use of quantum dots and arrays of nanoelectrodes to improve the analytical and bioanalytical capabilities of ECL. Finally, prospects and limits derived from the application of the above advanced nanomaterials to stimulate ECL emission are discussed

Automated Multiplexed Electrochemiluminescence based Immunoarrays for Prostate Cancer Biomarker Protein Detection & Genotoxic Screening Assays Using Electrochemiluminescence and LC-MS/MS

Cancer is the leading cause of death in U.S. next to deaths caused by heart diseases. Cancer causes extreme pain to the patient physical and mental health. Prostate cancer is one of the most common type of cancer in American men besides skin cancer. Even though extreme efforts are being placed in the field of science and technology to develop reliable cancer therapeutics, no cure was found to eradicate or alleviate the pain caused by cancer. Cancer biomarker proteins that are abnormally expressed and secreted into blood in a diseased state could provide early cancer diagnosis and provide better healthcare. This helps in addressing better therapeutic options in much early stages of cancer even before advanced tumors developed where the survival rates are extremely low. As of now for prostate cancer, serum levels of prostate specific antigen is widely used as a diagnostic tool. But over expression of PSA could be from many other prostate related issues leading to false positives. This further results in causing patients stress due to exaggerated diagnosis and treatment options. Detection of panel of prostate cancer biomarkers from serum sample simultaneous with high sensitivity and selectivity could provide valuable information for early cancer diagnostics and better treatment options. The primary goal of this thesis is to develop ECL based automated diagnostic platforms that can detect panel of prostate cancer biomarkers with high sensitivity and high throughput. The assay platforms being low cost, rapid and non-complex they can be easily translated into public health care much faster and provide conclusive results with no ambiguity for better treatment options. This thesis explores many new device fabrication, automation strategies and liquid handing systems for easier completion of sensitive immunoassays with ultralow detection limits. Nano structured detection platforms and RuBPY dye doped silica nanoparticles have been used as amplification strategies to detect the serum proteins at low femtogram levels. We successfully developed immunoassay platforms that can detect small protein panel (3 proteins) to large protein (8 proteins) panel. We demonstrated 3-D printing as rapid fabrication tool to make microfluidic immunoarrays that enabled low cost sensors with relatively low sample volume requirements. The developed ECL arrays holds great promise in accurate detection of early stages of cancer in physician’s clinic and point of care settings

Automated 3‑D Printed Arrays to Evaluate Genotoxic Chemistry: E‑Cigarettes and Water Samples

A novel, automated, low cost, three-dimensional (3-D) printed microfluidic array was developed to detect DNA damage from metabolites of chemicals in environmental samples. The electrochemiluminescent (ECL) detection platform incorporates layer-by-layer (LbL) assembled films of microsomal enzymes, DNA and an ECL-emitting ruthenium metallopolymer in ∼10 nm deep microwells. Liquid samples are introduced into the array, metabolized by the human enzymes, products react with DNA if possible, and DNA damage is detected by ECL with a camera. Measurements of relative DNA damage by the array assess the genotoxic potential of the samples. The array analyzes three samples simultaneously in 5 min. Measurement of cigarette and e-cigarette smoke extracts and polluted water samples was used to establish proof of concept. Potentially genotoxic reactions from e-cigarette vapor similar to smoke from conventional cigarettes were demonstrated. Untreated wastewater showed a high genotoxic potential compared to negligible values for treated wastewater from a pollution control treatment plant. Reactivity of chemicals known to produce high rates of metabolite-related DNA damage were measured, and array results for environmental samples were expressed in terms of equivalent responses from these standards to assess severity of possible DNA damage. Genotoxic assessment of wastewater samples during processing also highlighted future on-site monitoring applications

3d-printed bioanalytical devices

While 3D printing technologies first appeared in the 1980s, prohibitive costs, limited materials, and the relatively small number of commercially available printers confined applications mainly to prototyping for manufacturing purposes. As technologies, printer cost, materials, and accessibility continue to improve, 3D printing has found widespread implementation in research and development in many disciplines due to ease-of-use and relatively fast design-to-object workflow. Several 3D printing techniques have been used to prepare devices such as milli- and microfluidic flow cells for analyses of cells and biomolecules as well as interfaces that enable bioanalytical measurements using cellphones. This review focuses on preparation and applications of 3D-printed bioanalytical devices

Paper-based electrochemiluminescent screening for genotoxic activity in the environment

A low cost, microfluidic paper electrochemical device (mu PED) was fabricated using screen printing of electrodes and heat transfer of patterned wax paper onto filter paper. The mu PED features films of a light-emitting ruthenium metallopolymer, microsomal metabolic enzymes, and DNA to detect potential genotoxic pollutant activity in environmental samples. Unlike conventional analytical methods that detect specific pollutant compounds, the mu PED was designed to rapidly measure the presence of genotoxic equivalents in environmental samples with the signal related to benzo[a]pyrene (B[a]P) as a reference standard. The analytical end point is the detection of DNA damage from metabolites produced in the device using an electrochemiluminescence output measured with a charge-coupled device (CCD) camera. Proof-of-concept of this measurement was established for smoke, water, and food samples. The mu PED provides a rapid screening tool for on-site environmental monitoring that specifically monitors the genotoxic reactivity of metabolites of toxic compounds present in the samples

Using Ubiquitin Binders to Decipher the Ubiquitin Code

International audienc

3d-printed bioanalytical devices

While 3D printing technologies first appeared in the 1980s, prohibitive costs, limited materials, and the relatively small number of commercially available printers confined applications mainly to prototyping for manufacturing purposes. As technologies, printer cost, materials, and accessibility continue to improve, 3D printing has found widespread implementation in research and development in many disciplines due to ease-of-use and relatively fast design-to-object workflow. Several 3D printing techniques have been used to prepare devices such as milli- and microfluidic flow cells for analyses of cells and biomolecules as well as interfaces that enable bioanalytical measurements using cellphones. This review focuses on preparation and applications of 3D-printed bioanalytical devices