Multiplexed label-free optical biosensor for medical diagnostics.
This paper describes a new multiplexed label-free biosensor. The detection technology is based on nanostructured gold-polymer surfaces. These surfaces support surface plasmon resonance modes that can be probed by a miniaturized optical setup. The optical characterization of the sensing chip shows the sensitivity and the limit-of-detection to refractive index changes. Moreover, by studying the progressive adhesion of molecular monolayers of polyelectrolytes, the decay of the plasmonic mode electric field above the surface has been reconstructed. A multiplexed label-free biosensing device is then described and characterized in terms of sensitivity, lateral resolution, and sensitivity to a model biological assay. The sensitivity in imaging mode of the device is of the order of 10-6 refractive index units, while the measured lateral resolution is 6.25 μm within a field of view of several tenths of mm2, making the instrument unique in terms of multiplexing capability. Finally, the proof-of-concept application of the technology as a point-of-care diagnostic tool for an inflammatory marker is demonstrated.
Humanitas Clinical and Research Center, Department of Inflammation and Immunology, 20089 Rozzano, Milan, Italy.
Barbara
B
Bottazzi
University of Pavia, Physics Department, via Bassi 6, 27100 Pavia, Italy.
Lucia
L
Fornasari
Plasmore S.r.l., Via Deledda 4, 21020 Ranco, Varese, Italy.
Ana
A
Frangolho
University of Pavia, Physics Department, via Bassi 6, 27100 Pavia, Italy.
Silvia
S
Giudicatti
Humanitas Clinical and Research Center, Department of Inflammation and Immunology, 20089 Rozzano, Milan, Italy.
Alberto
A
Mantovani
University of Pavia, Physics Department, via Bassi 6, 27100 Pavia, Italy.
Franco
F
Marabelli
Plasmore S.r.l., Via Deledda 4, 21020 Ranco, Varese, Italy.
Gerardo
G
Marchesini
Plasmore S.r.l., Via Deledda 4, 21020 Ranco, Varese, Italy.
Paola
P
Pellacani
University of Pavia, Physics Department, via Bassi 6, 27100 Pavia, Italy.
Rita
R
Therisod
Plasmore S.r.l., Via Deledda 4, 21020 Ranco, Varese, Italy.
Andrea
A
Valsesia
D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D002138:Calibration; D004573:Electrolytes; D006046:Gold / Q000737:chemistry; D006801:Humans; D007249:Inflammation; D049329:Nanostructures; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods; D055095:Optics and Photonics; D011108:Polymers / Q000737:chemistry; D051381:Rats; D012031:Refractometry; D018805:Sepsis / Q000175:diagnosis*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D020349:Surface Plasmon Resonance / Q000295:instrumentation
D004573:Electrolytes; D011108:Polymers; D012710:Serum Albumin, Bovine; D006046:Gold