Photoelectric Silk via Genetic Encoding and Bioassisted Plasmonics

Abstract

Genetically encoded photoelectric silk that can convert photons to electrons (light to electricity) over a wide visible range in a self‐power mode is reported. As silk is a versatile host material with electrical conductivity, biocompatibility, and processability, a photoelectric protein is genetically fused with silk by silkworm transgenesis. Specifically, mKate2, which is conventionally known as a far‐red fluorescent protein, is used as a photoelectric protein. Characterization of the electrochemical and optical properties of mKate2 silk allows designing a photoelectric measurement system. A series of in situ photocurrent experiments support the sensitive and stable performance of photoelectric conversion. In addition, as a plasmonic nanomaterial with a broad spectral resonance, titanium nitride (TiN) nanoparticles are biologically hybridized into the silk glands, taking full advantage of the silkworms’ open circulatory system as well as the absorption band of mKate2 silk. This biological hybridization via direct feeding of TiN nanoparticles further enhances the overall photoelectric conversion ability of mKate2 silk. It is envisioned that the biologically derived photoelectric protein, its ecofriendly scalable production by transgenic silkworms, and the bioassisted plasmonic hybridization can potentially broaden the biomaterial choices for developing next‐generation biosensing, retina prosthesis, and neurostimulation applications.

Edible Matrix Code with Photogenic Silk Proteins

“…Recombinant silk proteins can be mass-produced with several host systems . Specifically, genetic fusion of silk fibroin and fluorescent protein is readily available via piggyBac transposase and clustered regularly interspaced short palindromic repeats (CRISPR) tools. − These biomanufacturing methods are highly ecofriendly, scalable, and sustainable. ,, Fluorescent proteins are often included in genetically modified dietary products for oral consumption . When compared with common food allergens, fluorescent proteins do not have common allergen epitopes and are well degraded during gastric digestion .…”

Bioinkjet Printing and Protein Tagging of Camouflaged Biosafe Quick Response Codes for Medicine Authentication

“…From an edible perspective, the silk fibroin is not only recognized as safe by the FDA as a food additive, [47] but it is also biocompatible, digestible, noncytotoxic, nonantigenic, and noninflammatory. [27,[48][49][50][51][52][53] From an optical perspective, silk fibroin exhibits negligible optical absorption in the visible and NIR wavelength range of 400−1000 nm (Figure S4, Supporting Information). From a manufacturing perspective, the easy processability of the silk fibroin offers a scalable production option (Figures S5,S6, Supporting Information); however, printing fine patterns using water-based inkjet inks on a silk fibroin print sheet is not straightforward because the printing ability is affected by the surface properties of the print sheets.…”

Ectopic expression of sericin enables efficient production of ancient silk with structural changes in silkworm

“…Therefore, innovative reprogramming of the genomes of SG cells to alter the structure and characteristics of the silk ber is highly desirable 21,22 . An attractive method is to directly integrating special functional ber protein genes into the silkworm genome has been described to aid in achieving high-e ciency expression in SGs, such as the expression of a high-strength spider silk protein gene in silkworm SGs to obtain silk bers with improved mechanical properties [23][24][25][26] , and the expression of fusions of optical functional protein and silk protein to obtain photoelectric silk or uorescent silk 27,28 .…”