Flexible Biochips for Detection of Biomolecules

Abstract

Miniaturization of biosensors is envisaged by the development of biochips consisting of parallel microarray patterns of binding sites on rigid substrates, such as glass or silicon. Thin plastic substrates are promising flexible alternatives because of the possibility for large-area roll-to-roll manufacturing of disposable chips at lower costs. Mature optical lithography technology faces many challenges when used to pattern flexible foils as a result of the substrate instabilities, especially at higher temperatures. In this work, flexible biochips with gold electrode patterns were fabricated on thin polyethylene naphthalate (PEN) foils using photolithography. The gold electrode structures of the chips were manufactured by direct metal patterning and by lift-off processing. Both methodologies resulted in well-defined electrode patterns as concluded from optical microscopy and scanning electron microscopy (SEM) characterization and resistance measurements. The biochips were successfully employed for the electrical and optical detection of DNA molecules. The DNA detection was based on the immobilization of capture DNA between electrode gaps, hybridization with biotin-labeled target DNA, and enzymatic silver enhancement.

A microfluidic platform for chip-based DNA detection using SERS and silver colloids

“…Appropriate materials for the chip platform are glass, polymers or hydrogels. 26,27 Here, we use glass chips for the immobilisation of the capture DNA. For the DNA analysis, different capture DNA strands were immobilised on the chip substrate.…”

Application of thin metal film elements in bioanalysis

“…A conductance change due to protein adsorption was evaluated using bovine serum albumin (BSA) as a sample [52]. The effect of resistance change upon molecule adsorption could be further enhanced by addition of functionalized particles into the detection system [53,54].…”

Polymer-based technology platform for robust electrochemical sensing using gold microelectrodes

“…The substrate material, PEN, is a leading candidate for organic thin film transistors and organic light emitting diodes [2]. In the literature there are a number of reported fabrication processes available to pattern materials on PEN, including direct/lift-off photolithography [4], roll-to-roll photolithography [19], digital (mask) lithography [20] [25,26], have a minimum feature size of 20 µm, or the fabrication method is not described in detail. Fully described here is the production of µEs of 6 µm width with a high chemical and electrochemical robustness.…”