Portable tumor biosensing of serum by plasmonic biochips in combination with nanoimprint and microfluidics

Abstract

Plasmonic sensing has a great potential in the portable detection of human tumor markers, among which the carcinoembryonic antigen (CEA) is one of the most widely used in clinical medicine. Traditional plasmonic and non-plasmonic methods for CEA biosensing are still not suitable for the fast developing era of Internet of things. In this study, we build up a cost-effective plasmonic immunochip platform for rapid portable detection of CEA by combining soft nanoimprint lithography, microfluidics, antibody functionalization, and mobile fiber spectrometry. The plasmonic gold nanocave array enables stable surface functionality, high sensitivity, and simple reflective measuring configuration in the visible range. The rapid quantitative CEA sensing is implemented by a label-free scheme, and the detection capability for the concentration of less than 5 ng/ml is achieved in clinical experiments, which is much lower than the CEA cancer diagnosis threshold of 20 ng/ml and absolutely sufficient for medical applications. Clinical tests of the chip on detecting human serums demonstrate good agreement with conventional medical examinations and great advantages on simultaneous multichannel detections for high-throughput and multi-marker biosensing. Our platform provides promising opportunities on low-cost and compact medical devices and systems with rapid and sensitive tumor detection for point-of-care diagnosis and mobile healthcare.

Selective light trapping of plasmonic stack metamaterials by circuit design

“…25 The software Comsol Multiphysics is used for the full wave simulation based on the finite element method (FEM). 26 In the optical simulation, the adaptive inhomogeneous tetrahedral meshing is used to discretize the subwavelength unit cell, and the essential wave ports with Floquet periodic boundary conditions are adopted. The minimum edge length of the mesh element is as small as 0.05 nm to ensure the simulation convergence and reproducibility.…”

Ultrathin sputter-deposited plasmonic silver nanostructures

“…These kinds of structures have been investigated as plasmonic colour lters, 22,23 in plasmon-enhanced uorescence, 24 as well as for plasmonic biosensors. 25,26 The present work aims to combine the aforementioned aspects of simple nanostructure fabrication by NIL (without further li-off or etching steps) with ultrathin Ag deposition to form plasmonic disk-hole arrays with high visible transmission and strong plasmonic resonance in the near-infrared range.…”

3D nanoplasmonic biosensor for detection of filopodia in cells

“…Therefore, NIL has the advantage of providing low cost and high throughput technology for fabricating portable detection microsystems with nanoplasmonic biosensors. [27][28][29][30] In this work, 3D symmetrical and asymmetrical nanopillars were developed and fabricated by NIL. 3D asymmetrical nanopillars with sloped sidewall structures were formed and Fano resonance was observed.…”