Lab-on-a-Chip Archives

A particle-based microfluidic molecular separation integrating surface-enhanced Raman scattering sensing for purine derivatives analysis

A particle-based microfluidic molecular separation (PMMS) system was developed which integrates SERS substrate to separate complicate molecule mixture followed by in situ SERS detection. The platform consists of an automatic microfluidic control system to precisely control the sample and reagent flow. The miniaturized PMMS–SERS system enables an easy-to-use and sensitive analyte detection, which could be … Read more

Localized surface plasmon resonance (LSPR) sensor integrated automated microfluidic system for multiplex inflammatory biomarker detection

A localized surface plasmon resonance (LSPR) sensor enables continuous and dynamic inflammatory biomarker detection, we utilized to perform label-free molecule sensing. The small LSPR sensing mechanism simplifies optical setup and can be easily integrated with a microfluidic device. An automated microfluidic control system was developed to control reagent guiding and switching in the immunoassay with … Read more

Lab-on-a-Chip Application: Microfab-less Microfluidics for a Portable Hybrid Microchip-Capillary Electrophoresis Device

Microfluidic devices, with their potential for portability and rapid analysis times, can bring cost-effective flexibility to modern analytical chemistry applications. However, the design and fabrication of microchips can involve trade-offs between cost, flexibility of configuration, and ideal surface properties or performance. To circumvent these drawbacks, we have developed a hybrid platform consisting of simple microfabricated … Read more

Lab-on-a-Chip uProcess™ Application: Continuous Dispensing

Particularly in biological experiments, it is necessary to deliver fluid at flow rates of ≤ 1μl/min over experiment times of hours to days. As a result, a relatively large total volume is dispensed to the experiment, sometimes as much as 1-10 ml. In lab-on-a-chip experiments, a small overall experimental platform is often desired. This creates the challenge of … Read more

Lab-on-a-Chip Application: Circulating Tumor Cell Immuncapture Automation

The manipulation of biological samples for diagnostic purposes requires reproducibility and simplicity to be useful in practice. As microfluidic devices transition towards use in medical diagnostics, traditional handheld syringe pumps can be too bulky and laborious for medical procedures that require quick turnaround times. Here, we discuss the evaluation of a portable breadboard platform that … Read more

Hydrodynamic Focusing using Integrated Modular Pumps, Valves, Connectors & Imaging

Hydrodynamic focusing capitalizes on the inherent advantages of the flow physics of a microfluidic system to overcome functional challenges encountered in microfluidic conditions such as mixing and the delivery of particles such as cells for counting. Hydrodynamic focusing requires reproducible flow rates, valving, and automated control of pumps and valves to direct the processes on … Read more

Field Amplified Sample Stacking (FASS) for Sample Concentration in a Nanochannel

A ubiquitous problem in analytical chemistry is the push to increase signal-to-noise (S/N) and to lower the limits of detection (LOD) for many sample separation methods. Low S/N is typically due to the inherent low concentration of the sample in the system and the band-broadening of the sample in dead volumes of the analytical system. … Read more

Performing an Electrokinetic Gated Injection in a Nanochannel

The microfluidic chip platform offers an advantage for electrokinetic chemical separations by eliminating the dead volume normally encountered with tubing connections. In order to capitalize on this advantage, sample injections must be performed on chip. The gated injection loads a variable injection volume by controlling velocity and injection time. The gated injection controls plug size … Read more

Prediction of trapping zones in an insulator-based dielectrophoretic device

Baylon-Cardiel, J.L.; Lapizco-Encinas,B.L.;Reyes-Betanzo,C.; Chavez-Santoscoy,A.V.; Martınez-Chapa, S.O. Prediction of trapping zones in an insulator-based dielectrophoretic device Lab-on-a-Chip, 2009, 9, 2896–2901. Abstract A mathematical model is implemented to study the performance of an insulator-based dielectrophoretic device. The geometry of the device was captured in a computational model that solves Laplace equation within an array of cylindrical insulating … Read more