Paving the Way to Industrially Fabricated Disposable and Customizable Surface‐Enhanced Raman Scattering Microfluidic Chips for Diagnostic Applications

Abstract

Both surface‐enhanced Raman scattering (SERS) spectroscopy and microfluidics are increasing their presence in industry. The integration of SERS into microfluidic chips is relevant for label‐free biosensing and can expand the function of microfluidics to provide an efficient platform for on‐site biochemical analysis equipped with the powerful sensing capability of SERS. Herein, the design and industry manufacturing of reliable and cost‐effective disposable SERS microfluidic chips using high throughput technologies of injection molding and roll‐to‐roll are demonstrated. The SERS microfluidic chip is made of cyclic olein copolymers and of an ultrathin nanostructured polyethylene terephthalate foil covered by a plasmonic nanostructured Ag film, enabling Raman readout through it. This ultrathin plasmonic Ag‐coated PET layer overcomes the drawbacks of SERS through thick polymeric microfluidic cells, i.e., it avoids strong fluorescence signals interfering with the Raman measurements and avoids high working distances. The achieved SERS enhancement in the range 105–106 is demonstrated by probing 100 nl of 1 M rhodamine and of 10−12 m crystal violet with a > 90% reproducible signal, with large‐area uniformity on all the SERS area of 20 mm 2 and good stability of the signal over months. Therefore, this approach of SERS microfluidic chips provides an industrially viable customizable and cost‐effective route toward disposable, point‐of‐care diagnostic applications.

Trends of Biosensing: Plasmonics through Miniaturization and Quantum Sensing

“…Although SERS/microfluidics have demonstrated excellent results, and both SERS spectroscopy and microfluidics are growing in popularity, there is significant interest in adopting these technologies in the industry. The development of dependable, affordable disposable SERS microfluidic chips employing high-throughput manufacturing techniques like injection molding and roll-to-roll [119] as well as the use of transparent polymers for the construction of microsystems [120] are examples of efforts in this approach.…”

A novel LoC-SERS device integrated with aptamer recognition strategy for the highly sensitive and specific detection of thrombin and platelet-derived growth factor-B

“…Some pumpless fluid control methods, including pre-degassing, capillary force, and finger drive, were suggested and used in several real-world applications to address this issue. 41,42 Capillary force is created via a hydrophilic surface treatment, and it is further strengthened by channels with a comb shape. Serological detection has employed the capillary driver design as a platform for SERS detection with success.…”