Publications by Venkataragavalu Sivagnanam

Exploring Living Multicellular Organisms, Organs, and Tissues Using Microfluidic Systems

Martinus Gijs, Venkataragavalu Sivagnanam

American Chemical Society2013

Microchannel-guided capture antibody patterning on beads for multiple protein detection arrays

Martinus Gijs, Venkataragavalu Sivagnanam, Hüseyin Cumhur Tekin, Sébastien Vaneberg

We present the rapid fabrication of custom protein micro-arrays, in less than 35 minutes, on the surface of immobilized beads using microchannel-guided flows driven by a single syringe pump. The commercially available beads provide robust micro-array surfa ...

2011

Chaotic mixing using source-sink microfluidic flows in a PDMS chip

Abdeljalil Sayah, Martinus Gijs, Caroline Vandevyver, Venkataragavalu Sivagnanam, Hüseyin Cumhur Tekin, Ata Tuna Ciftlik

We present an active fixed-volume mixer based on the creation of multiple source–sink microfluidic flows in a polydimethylsiloxane (PDMS) chip without the need of external or internal pumps. To do so, four different pressure-controlled actuation chambers a ...

Springer-Verlag2011

High-Performance Protein Preconcentrator Using Microchannel-Integrated Nafion Strip

Martinus Gijs, Venkataragavalu Sivagnanam, Meng Shen, Hui Yang

A microfluidic device for protein preconcentration based on the electrokinetic trapping principle is proposed. It comprises a Nafion strip which is simply cut from a commercially available membrane and integrated into a polydimethylsiloxane (PDMS) microflu ...

IEEE2011

Microfluidic Protein Preconcentrator Using a Microchannel-Integrated Nafion Strip: Experiment and Modeling

Martinus Gijs, Venkataragavalu Sivagnanam, Meng Shen

We propose a simple microfluidic device for protein preconcentration based on the electrokinetic trapping principle. It comprises a narrow Nafion strip that is simply cut from a commercial membrane and is integrated into a molded poly(dimethylsiloxane) (PD ...

American Chemical Society2010

Bioconjugated lanthanide luminescent helicates as multilabels for lab-on-a-chip detection of cancer biomarkers

Martinus Gijs, Jean-Claude Bünzli, Caroline Vandevyver, Anne-Sophie Chauvin, Venkataragavalu Sivagnanam, Bo Song, Vanesa Fernandez Moreira, Hans-Anton Lehr

The lanthanide binuclear helicate [Eu2(LC2(CO2H))3] is coupled to avidin to yield a luminescent bioconjugate EuB1 (Q ¼ 9.3%, s(5D0) ¼ 2.17 ms). MALDI/TOF mass spectrometry confirms the covalent binding of the Eu chelate and UV-visible spectroscopy allows o ...

2010

Microfluidic Immunoassays Based on Self-Assembled Magnetic Bead Patterns and Time-Resolved Luminescence Detection

Venkataragavalu Sivagnanam

Microfluidic bio-assays have emerged as the most privileged solutions and provide the basis for the realization of miniaturized bio-analytical systems and clinical diagnostic devices that are portable, user-friendly and cost-effective (Lab-on-a-chip). Two ...

EPFL2010

Study of Spatio-Temporal Immunofluorescence on Bead Patterns in a Microfluidic Channel

Martinus Gijs, Venkataragavalu Sivagnanam, Hui Yang

We performed a direct immunoassay inside a microfluidic channel on patterned streptavidin-coated beads, which captured fluorescently-labeled biotin target molecules from a continuous flow. We arranged the beads in a dot array at the bottom of the channel a ...

American Institute of Physics2010

On-chip immunoassay using electrostatic assembly of streptavidin-coated bead micropatterns

Martinus Gijs, Caroline Vandevyver, Venkataragavalu Sivagnanam

We propose an original concept for a sandwich immunoassay that is completely performed on-chip using streptavidin-coated beads as substrate. The latter are electrostatically self-assembled on aminosilane micropatterns at the bottom of a microfluidic channe ...

2009

Sandwich immunoassay on a microfluidic chip using patterns of electrostatically self-assembled streptavidin-coated beads

Martinus Gijs, Caroline Vandevyver, Frédéric Lacharme, Venkataragavalu Sivagnanam

In this paper, we demonstrate a bead-based microfluidic immunoassay using self-assembled streptavidin-coated bead micropatterns. The beads are assembled on the microfluidic channel surface using electrostatic forces between the negatively-charged streptavi ...

Elsevier2009

Time-resolved lanthanide luminescence for lab-on-a-chip detection of biomarkers on cancerous tissues

Martinus Gijs, Jean-Claude Bünzli, Caroline Vandevyver, Venkataragavalu Sivagnanam, Bo Song, Hans-Anton Lehr

PDMS-based microfluidic devices combined with lanthanide-based immunocomplexes have been successfully tested for the multiplex detection of biomarkers on cancerous tissues, revealing an enhanced sensitivity compared to classical organic dyes. ...

2009

Time-Resolved Luminescence for Immunohistochemical Detection of Cancer Biomarkers in a Lab-on-a-Chip

Martinus Gijs, Jean-Claude Bünzli, Caroline Vandevyver, Venkataragavalu Sivagnanam, Ata Tuna Ciftlik

2009

On-chip immunoassay using electrostatic assembly of streptavidin-coated bead micropatterns

Martinus Gijs, Caroline Vandevyver, Venkataragavalu Sivagnanam, Bo Song, Hui Yang

We propose an original concept for a sandwich immunoassay that is completely performed on-chip using streptavidin-coated beads as substrate. The latter are electrostatically self-assembled on aminosilane micropatterns at the bottom of a microfluidic channe ...

2009

Micropatterning of protein-functionalized magnetic beads on glass using electrostatic self-assembly

Abdeljalil Sayah, Martinus Gijs, Caroline Vandevyver, Venkataragavalu Sivagnanam

We demonstrate a simple and fast method for self-assembly-driven micropatterning of protein functionalized magnetic beads on glass. We use positively charged aminosilane micro-patterns as template for selective immobilization of streptavidin-coated beads b ...

2008

Bead-based single protein micro-array realized through electrostatic self-assembly of carboxylated beads

Abdeljalil Sayah, Martinus Gijs, Venkataragavalu Sivagnanam

We report here a simple method, based on electrostatic self-assembly, for realizing bead-based single protein micro-arrays. We generate positively charged surface micro-patterns on a glass substrate and use them as template for adsorbing negatively-charged ...

2008

Micropatterning of Streptavidin-Functionalized Magnetic Beads on Glass Using Electrostatic Self-Assembly

Abdeljalil Sayah, Martinus Gijs, Caroline Vandevyver, Venkataragavalu Sivagnanam

2007

Bead-based protein microarrays realized through electrostatic self-assembly of carboxylated beads

Abdeljalil Sayah, Martinus Gijs, Venkataragavalu Sivagnanam

We report here a simple method, based on electrostatic self-assembly, for realizing bead-based single protein microarrays. We generate positively-charged surface micro-patterns on a glass substrate and used them as the template for adsorbing negatively-cha ...

2007

Ultra-thick micro-optical components using the PRISM photosensitive flexopolymer

Abdeljalil Sayah, Martinus Gijs, Virendra Kumar Parashar, Venkataragavalu Sivagnanam

We present the photosensitive flexopolymer PRISM as a new promising material for the realization of thick optical components. The PRISM flexopolymer can be directly polymerized using conventional UV exposure and is simply developed in a water-based solutio ...

2007

Micropatterning of streptavidin-coated magnetic microbeads in-situ in a microfluidic channel using electrostatic self-assembly

Abdeljalil Sayah, Martinus Gijs, Venkataragavalu Sivagnanam, Hüseyin Cumhur Tekin

2007