Donor-σ-Acceptor Dyad-Based Polymers for Portable Sensors: Controlling Photoinduced Electron Transfer via Tuning the Frontier Molecular Orbital Energies of Acceptors

Abstract

In this study, we synthesized three novel aromatic imide-based conjugated donor­(D)-σ-acceptor (A) dyad-based polymers showing different photophysical properties. These D-σ-A dyad-based polymers (e.g., BDTBT-NI, BDTBT-NDI, and BDTBT-PDI) consist of the same conjugated donor main chains (benzodithiophene-bithiophene (BDTBT)) and side chains bearing different imide acceptors (naphthalimide (NI), naphthalene diimide (NDI), or perylenediimide (PDI)). The photophysical and electrochemical characteristics of the three polymers were studied using various methods, including UV–visible absorption, steady-state fluorescence, and time-resolved fluorescence experiments as well as cyclic voltammetry. As the acceptor strength of the side chain was increased, photoinduced electron transfer from the donor backbone to the acceptor side-chain moiety was found to occur more effectively. Among the three polymers, BDTBT-PDI was found to be used as an efficient extractor and portable naked-eye sensing probe for Fe2+ ions; notably, it exhibited a “turn-on” fluorescence response with a detection limit at a picomolar concentration. The BDTBT-PDI:Fe2+ complex was also used for ultrasensitive detection of spermine (with a Stern–Volmer constant of 6.7 × 106 M–1) in urine samples and was established as an efficient portable test kit for the real-time detection of spermine in the vapor released from fermented food samples. Finally, the “on–off” fluorescence behavior of BDTBT-PDI in the presence of Fe2+ and spermine enabled us to develop molecular logic gates using this polymer.

A combination of a graphene quantum dots–cationic red dye donor–acceptor pair and cucurbit[7]uril as a supramolecular sensor for ultrasensitive detection of cancer biomarkers spermine and spermidine

“…Over the years, many traditional techniques, such as chromatographic methods, 21 biosensors, 22 immunoassay-based methods, 23 as well as colorimetric and fluorimetric methods using small organic molecules as sensing probes, [24][25][26] to detect biogenic polyamines have received immense current attention. [21][22][23][24][25][26] Notably, the fabrication of a dye on a nanomaterial for the detection of biogenic amines is one of the recent strategies for potential real-life applications. 27 However, they sometimes lack selectivity due to nonspecific interactions by the amine functionality and often require the use of toxic organic solvents for sensing studies.…”

Tailoring the π–π stacking interaction among organic cations in hybrid metal halide crystals towards tunable light emission

“…The weak interaction in 23-CdCl and 23-ZnCl was further studied by the NCI analysis, which was calculated by using M06/def2SVP model based on DFT. [48][49][50] As displayed in Fig. 5a and b, the NCI calculation results clearly demonstrates the existences of p-p stacking and hydrogen bond interactions among 2,3 0bipyridinium cations in the 23-ZnCl crystal, while there is no p-p stacking interaction in the 23-CdCl crystal.…”

Perylene-diimide for organic solar cells: current scenario and prospects in molecular geometric, functionalization, and optoelectronic properties

“…72–74 However, early studies indicate that utilizing PDI as the acceptor does not function because it results in the formation of a large aggregation in the BHJ blend. 75–77 Disrupting the planarity of PDI s is a beneficial technique to suppress aggregation and boost photovoltaic performances, which can be used to overcome these bottlenecks. There have been three key approaches to reducing the production of large BHJ domains and rapid excimer formation, all of which have resulted in significantly enhanced photovoltaic performance: (1) twisted PDI derivatives at the bay/imide position; 78–82 (2) twisted PDI dimers at the 1,6,7,12-locations (“bay positions”) either directly or with a spacer; 83–87 and (3) bulky “swallow tail” PDI side chains at the imide position to introduce a highly twisted configuration in their packing (Fig.…”