High throughput label-free platform for statistical bio-molecular sensing

Abstract

Sensors are crucial in many daily operations including security, environmental control, human diagnostics and patient monitoring. Screening and online monitoring require reliable and high-throughput sensing. We report on the demonstration of a high-throughput label-free sensor platform utilizing cantilever based sensors. These sensors have often been acclaimed to facilitate highly parallelized operation. Unfortunately, so far no concept has been presented which offers large datasets as well as easy liquid sample handling. We use optics and mechanics from a DVD player to handle liquid samples and to read-out cantilever deflection and resonant frequency. Also, surface roughness is measured. When combined with cantilever deflection the roughness is discovered to hold valuable additional information on specific and unspecific binding events. In a few minutes, 30 liquid samples can be analyzed in parallel, each by 24 cantilever-based sensors. The approach was used to detect the binding of streptavidin and antibodies.

Detection methods for centrifugal microfluidic platforms

“…In the setup presented by Bosco et al (Bosco et al, 2011), the OPU is mounted on an x-y stage. By scanning cantilevers at different radial positions, it is possible to construct a 3D image of the cantilever surfaces, see surfaces whereas the formation of, for example, self-assembled layers of thiolated molecules yields smoother optical profiles.…”

“…The cantilevers are made of silicon or polymer with a length of 500 µm, a width of 100 µm and a thickness of 1 µm. The OPU is placed below the disc and the deflection profiles of the cantilevers are measured using the astigmatic detection mechanism normally used for autofocusing (Bosco et al, 2011). The OPU can measure the cantilever deflection with sub-nanometric resolution in Z direction.…”

Tackling reproducibility in microcantilever biosensors: a statistical approach for sensitive and specific end-point detection of immunoreactions

“…In addition, the size of these devices has been increasingly reduced which leads to higher device density and, more importantly, implies higher sensitivity. In addition, high throughput detection can readily be achieved by fabricating hundreds of cantilevers in arrays and by the fast read-out of their response by optical 14,[33][34][35] or electrical techniques 13,25 .…”

“…In this work, we examine the capability of micro-and nanocantilever biosensors in the static mode [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] for end point label-free immunoassays. In these devices, molecular recognition between the analyte and the receptor monolayer anchored on one side of a tiny cantilever induces a nanoscale bending as a consequence of the surface stress variation on the functionalized surface 32 .…”

Detection and photothermal actuation of microcantilever oscillations in air and liquid using a modified DVD optical pickup

“…As reported in [4], the astigmatic detection system common to most CD and DVD OPUs allows to register both linear displacement of the microcantilever with sub-nm resolution as well as two-dimensional angular displacements. Applications of such transducers as the basis of AFM instruments [5] as well as in scalable biomolecular sensing systems [6] are under investigation.…”