title: Aqueous multiphoton lithography with multifunctional silk-centred bio-resists.
abstract: Silk and silk fibroin, the biomaterial from nature, nowadays are being widely utilized in many cutting-edge micro/nanodevices/systems via advanced micro/nanofabrication techniques. Herein, for the first time to our knowledge, we report aqueous multiphoton lithography of diversiform-regenerated-silk-fibroin-centric inks using noncontact and maskless femtosecond laser direct writing (FsLDW). Initially, silk fibroin was FsLDW-crosslinked into arbitrary two/three-dimensional micro/nanostructures with good elastic properties merely using proper photosensitizers. More interestingly, silk/metal composite micro/nanodevices with multidimension-controllable metal content can be FsLDW-customized through laser-induced simultaneous fibroin oxidation/crosslinking and metal photoreduction using the simplest silk/Ag(+) or silk/[AuCl4](-) aqueous resists. Noticeably, during FsLDW, fibroin functions as biological reductant and matrix, while metal ions act as the oxidant. A FsLDW-fabricated prototyping silk/Ag microelectrode exhibited 10(4)-Ω(-1 ) m(-1)-scale adjustable electric conductivity. This work not only provides a powerful development to silk micro/nanoprocessing techniques but also creates a novel way to fabricate multifunctional metal/biomacromolecule complex micro/nanodevices for applications such as micro/nanoscale mechanical and electrical bioengineering and biosystems.
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
authors.forename: Yun-Lu
authors.initials: YL
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
authors.forename: Si-Ming
authors.initials: SM
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China.
authors.forename: Jing-Chun
authors.initials: JC
authors.lastname: Huang
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
authors.forename: Bo-Yuan
authors.initials: BY
authors.lastname: Zheng
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
authors.forename: Qi-Dai
authors.initials: QD
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China.
authors.forename: Zheng-Zhong
authors.initials: ZZ
authors.lastname: Shao
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China.|College of Physics, Jilin University, 119 Jiefang Road, Changchun 130023, China.
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Sun
mesh_terms: D000818:Animals; D012831:Bombyx; D005349:Fibroins / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D007834:Lasers; D049329:Nanostructures / Q000737:chemistry*; D012834:Silver / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D012834:Silver; D006046:Gold; D005349:Fibroins