Long-Wavelength Illumination-Induced Photocurrent Enhancement of a ZnPc Photocathodic Material for Bioanalytical Applications

Abstract

Herein, a novel photocathodic nanocomposite poly­{4,8-bis­[5-(2-ethylhexyl)-thiophen-2-yl] benzo­[1,2-b:4,5-b′]­dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)-carbonyl]­thieno­[3,4-b]­thiophene-4,6-diyl}/phthalocyanine zinc (PTB7-Th/ZnPc) with high photoelectric conversion efficiency under long-wavelength illumination was prepared to construct an ultrasensitive biosensor for the detection of microRNA-21 (miRNA-21), accompanied by a prominent anti-interference capability toward reductive substances. Impressively, the new heterojunction PTB7-Th/ZnPc nanocomposite could not only generate a strong cathodic photocurrent to improve the detection sensitivity under long-wavelength illumination (660 nm) but also effectively avoid the high damage of biological activity caused by short-wavelength light stimulation. Accordingly, by coupling with rolling circle amplification (RCA)-triggered DNA amplification to form functional biquencher nanospheres, a PEC biosensor was fabricated to realize the ultrasensitive analysis of miRNA-21 in the concentration range of 0.1 fM to 10 nM with a detection limit as low as 32 aM. This strategy provided a novel long-wavelength illumination-induced photocurrent enhancement photoactive material for a sensitive and low-damage anti-interference bioassay and early clinical disease diagnosis.

ZnPc based multifunctional devices designed as fast capacitors, rectifiers, infrared detectors and microwave resonators adequate for 6 G technology applications

“…Zinc phthalocyanine (ZnPc) in thin film forms have attracted the attention due to their wide range of applications in optoelectronics. This organic compound showed excellent performance when employed in the fabrication of biosensors [1], phototransistors [2], memory devices [3] and photo-catalysis [4]. As biosensors they showed ultrahigh sensitivity to miRNA-21 biomarkers within the range of 0.1fM-10 nM [1].…”

“…This organic compound showed excellent performance when employed in the fabrication of biosensors [1], phototransistors [2], memory devices [3] and photo-catalysis [4]. As biosensors they showed ultrahigh sensitivity to miRNA-21 biomarkers within the range of 0.1fM-10 nM [1]. In addition as phototransistors of the structure ITO/ZnPc/Al/ZnPc/Cu they showed red light current responsivity of 1.95 A W −1 [2].…”