research activities in 2007 - CSEM

Robust Label-Free Biosensor using BRIGHT [1] Technology
M. Wiki, F. Kehl, P. Seitz
Among the various biosensor technologies, optical biosensors are the most promising for cost-effective, sensitive and high-throughput biochemical
screening. They can easily analyse the response of a biochemical binding event without the need of any fluorescent labels. The optimized BRIGHT
technology fulfils the key requirements for optical biosensors, in particular sensor robustness and reduced time-to-result.
The requirements of biosensor instruments for research and
industrial needs today are copious, and a commercially
successful system must be capable of meeting the
expectations of a demanding user in the laboratory:
• Real-time and in situ monitoring
• Sensitive, stable and reproducible
• Detection technologies without the need of labels
• Reduction of cost, time and labor
Based on its successful WIOS principle [2] , CSEM has
developed during the past two years its BRIGHT technology
for use in label-free biosensor measurement systems. A
series of recent improvements has led to the realization of an
easy-to-use instrument, shown in Figures 1 and 2, providing
fast and accurate multi-channel dynamic measurements in
everyday lab use.
Figure 1: The BRIGHT technology is the basis of the versatile
biosensor instrument BR-8 of the CSEM startup company Dynetix
AG.
The BRIGHT technology (“Bio-layer optical Resonance
Interrogation for High Throughput”) allows sensitive, yet robust
label-free measurement of association and dissociation rates,
affinity constants, and determination of specificity of
bioreactive molecules. In the development of the BRIGHT
technology, great emphasis has been put on the expectations
of a typical laboratory user, with the goal of making his daily
work as simple, efficient and reliable as possible.
Therefore, the main focus in the development of the BRIGHTbased
biosensor instrument was its robustness, the
significantly reduced signal drift, elimination of optical and
electrical interferences, internal stray light rejection, as well as
substantial improvements of the electronics, temperature
stabilization, control software and signal processing
algorithms for efficient elimination of cross talk between the
different sensor channels.
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Figure 2: Table-top label-free biosensor instrument BR-8 including
temperature stabilization of the sensor chip SC-8.
Due to these improvements at the heart of the BRIGHT
technology, the long preparation time prior to a measurement
has been reduced dramatically: In commercial systems of
today, biosensor chips must often be prepared in advance and
stabilized in buffer solution overnight. Conversely, BRIGHT
technology reduces the preparation time “to a fraction of an
hour”, as reported by external research institutes during tests.
As a result, several consecutive measurements can now be
performed within a short time, and long delays between
measurements can be avoided, saving labor time and
increasing throughput.
The new biosensor system BR-8 allows the measurement of
up to 8 channels simultaneously, with negligible crosstalk
between the different channels. Measurements are carried out
conveniently and reliably thanks to the disposable, versatile
biosensor chip SC-8. Since no metals are used in the
construction of the transparent SC-8 chip, interference with
the biochemical reactions under investigation is eliminated.
Due to the increasing demand for the BRIGHT-based,
versatile biosensor instrument BR-8 by industrial and research
laboratories, CSEM has created the startup DYNETIX AG [3] at
its new Research Renter for Nanomedicine, in Landquart (GR)
for the commercialization of the BR-8 instrument.
[1] BRIGHT = Bio-layer optical Resonance Interrogation for High
Throughput
[2] WIOS = Wavelength interrogated integrated optical sensor
[3] www.dynetix.ch