Multicolor and erasable DNA photolithography

Abstract

The immobilization of DNA molecules onto a solid support is a crucial step in biochip research and related applications. In this work, we report a DNA photolithography method based on photocleavage of 2-nitrobenzyl linker-modified DNA strands. These strands were subjected to ultraviolet light irradiation to generate multiple short DNA strands in a programmable manner. Coupling the toehold-mediated DNA strand-displacement reaction with DNA photolithography enabled the fabrication of a DNA chip surface with multifunctional DNA patterns having complex geometrical structures at the microscale level. The erasable DNA photolithography strategy was developed to allow different paintings on the same chip. Furthermore, the asymmetrical modification of colloidal particles was carried out by using this photolithography strategy. This strategy has broad applications in biosensors, nanodevices, and DNA-nanostructure fabrication.

Figure 1

Chemical basis of DNA photolithography. (a) Structure of the photocleavable linker and reaction schematic. (b) Photocleavage process of DNA complex containing a photocleavable linker. (c) Cleavage kinetics of the DNA complex containing a photocleavable linker as observed by electrophoresis. (d) Plot of photocleavage fraction versus UV irradiation time.

Figure 2

Schematic of DNA photolithography with a photocleavable 2-nitrobenzyl linker-based DNA strand to generate a pattern with one color on the surface (1–5) Procedure of DNA photolithography and (6) green fluorescent pattern on the surface after photolithography. The scale bar is 200 μm.

Figure 3

Schematic of DNA photolithography with a photocleavable 2-nitrobenzyl linker-based DNA strand to generate patterns with two different colors on the surface. (1–8) DNA photolithography procedures for generating the multifunctional surface and (9–12) fluorescent patterns with two different colors on the surface after photolithography. The scale bars are 200 μm.

Figure 4

Schematic of erasable DNA photolithography. (1–9) Procedure of erasable DNA photolithography, and (10–12) green fluorescent patterns repeatedly generated using the same chip surface through erasable DNA photolithography. The scale bars are 200 μm.

Figure 5

Schematic procedure for producing particles with one-side DNA functionalization. Fluorescent detection of the particles (a) before UV irradiation and (b) after UV irradiation. (c) Self-assembled structure of the one-side LS1 functionalized large particles with complementary small particles A. (d) Self-assembled structure of LS1 functionalized large particles with complementary small particles A.

Figure 6

Schematic procedure for producing particles with two different DNA functionalization at different sides. (a) Self-assembled structure of LS2 DNA functionalized large particles with complementary small particles A. (b) Self-assembled structure of UV irradiated LS2 DNA functionalized large particles with complementary small particles A. (c) Self-assembled structure of LS2 and LS3 functionalized large particles with complementary small particles A or B. (d) Self-assembled structure of LS2 and LS3 functionalized large particles with complementary small particles A and B.