High sensitivity plasmonic biosensor based on nanoimprinted quasi 3D nanosquares for cell detection

Abstract

Quasi three-dimensional (3D) plasmonic nanostructures consisting of Au nanosquares on top of SU-8 nanopillars and Au nanoholes on the bottom were developed and fabricated using nanoimprint lithography with simultaneous thermal and UV exposure. These 3D plasmonic nanostructures were used to detect cell concentration of lung cancer A549 cells, retinal pigment epithelial (RPE) cells, and breast cancer MCF-7 cells. Nanoimprint technology has the advantage of producing high uniformity plasmonic nanostructures for such biosensors. Multiple resonance modes were observed in these quasi 3D plasmonic nanostructures. The hybrid coupling of localized surface plasmon resonances and Fabry-Perot cavity modes in the quasi 3D nanostructures resulted in high sensitivity of 496 nm/refractive index unit. The plasmonic resonance peak wavelength and sensitivity could be tuned by varying the Au thickness. Resonance peak shifts for different cells at the same concentration were distinct due to their different cell area and confluency. The cell concentration detection limit covered a large range of 5 × 10(2) to 1 × 10(7) cells ml(-1) with these new plasmonic nanostructures. They also provide a large resonance peak shift of 51 nm for as little as 0.08 cells mm(-2) of RPE cells for high sensitivity cell detection.

Flexible Localized Surface Plasmon Resonance Sensor with Metal–Insulator–Metal Nanodisks on PDMS Substrate

“…By analyzing this LSPR shift, small-sized entities, such as biological antibodies and low-concentration analytes, can be detected 9 , 10 . This technique can be used for monitoring viruses and cancer cells 11 – 13 . Thus, LSPR sensors have considerable potential for providing high sensitivity and label-free methods for emerging areas of biological detection.…”

Femtosecond Laser Micro/Nano-manufacturing: Theories, Measurements, Methods, and Applications

“…In addition, for processing proteinaceous materials, femtosecond lasers offer a distinct advantage. Unlike nanoimprinting and ultraviolet lithography [126,127], femtosecond laser direct writing offers an excellent threedimensional fabrication ability and can be used to produce devices with nanometer precision. More importantly, biomaterials prepared using femtosecond laser direct writing can retain the biological activity of biomaterials [128,129].…”

Compact High-Gain Si-Imprinted THz Antenna for Ultrahigh Speed Wireless Communications

“…11, a glass bead was used as a stamp to imprint photoresist on glass. The imprint process was carried out at 95 • C and 5 bar for 10 min, and 395 nm ultraviolet (UV) exposure for 2 min [30]. After demolding the glass bead at 20 • C, a spherical concave cavity was generated in the SU-8 over the glass substrate.…”