Supramolecular aggregates as sensory ensembles

Abstract

As a new emerging area in chemical sensing, sensing using supramolecular aggregates exhibits unique advantages over that using conventional small-molecule chemical sensors, in terms of high sensitivity and selectivity, and the simplicity of the sensory building blocks. This Feature Article outlines the recent research progress made in sensing based on induced supramolecular aggregation-disaggregation. The reviewed sensory building blocks, in general, in the form of a small molecular sensor, yet with a much simpler structure, which form aggregates, are those of perylene derivatives, pyrene derivatives, tetraphenylethylene derivatives, metallophilic species and metal-organic frameworks.

Perylene Diimide-Based Fluorescent and Colorimetric Sensors for Environmental Detection

“…Developing chemical sensor techniques for trace-level detection of environment hazardous substances, especially heavy metal ions and organic pollutants, remains essential and has drawn increasing research efforts in past decades. Compared with the conventional bench-top analytical instrumental techniques such as chromatography, mass spectrometry, infrared spectrometry, electrochemistry (which normally require expensive, bulky in size and complicated in operation equioment), chemosensors have attracted much more research attention from the chemistry and material science community, mainly due to the unique features of chemosensors, e.g., low-cost, small-size for portability, high sensitivity and selectivity, and quick response for real-time on-site detection [1][2][3][4][5][6]. Among all kinds of chemosensors, optical sensors based on fluorescence or colorimetric signal modulation exhibit superiority regarding system simplicity for facile operation, and non-destructive detection with high sensitivity and selectivity (in some cases, detection can even be visualized by naked-eyes) [4][5][6].…”

“…PDI molecules possess highly tailorable structures, versatile electronic and optical properties such as excellent electron affinity, strong optical absorption, remarkable monomeric fluorescence with near 100% quantum yields (φ) in solvents, desirable excited state lifetime, etc. [3][4][5][6]. In particular, PDIs have unique thermal and photochemical stability, i.e.…”

“…In particular, PDIs have unique thermal and photochemical stability, i.e. resistance to photobleaching and heat, which both are critical for practical use as optical sensors [4][5][6]. One unique feature of PDI is that the two imide-positions are node in π-orbital, and thus substitution at these positions does not change significantly the electronic property of PDI (e.g., UV-vis adsorption).…”

“…Additionally, PDI molecules (owing to their rigid planar geometry) are prone to forming supramolecular H-aggregates via π-π stacking along with the decreased molecular fluorescence and hypsochromic shift of the absorption band as a result of the strong π-π electronic interaction [3]. Benefiting from such supramolecular assembly-disassembly behavior accompanied with significant optical change (especially fluorescence turn-off/ turn-on and colorimetric change), PDIs are especially suitable for fluorescence and colorimetric sensors with high selectivity and sensitivity [5,6].…”

Organic Nanoprobes for Fluorescence and 19F Magnetic Resonance Dual‐Modality Imaging

“…[3,4] Among the various combination of imaging modalities, a combination of fluorescence imaging (FI) and magnetic resonance imaging (MRI) [5][6][7][8][9][10][11] has the characteristic of complementary advantages. [12,13] Compared with other bioimaging techniques, FI displays more advantages of high sensitivity, easy operation, and cost-effectiveness, [14][15][16][17][18][19] which can also trace real-time cellular processes over a long period of time but lacks penetration depth for the internal organs, especially in view of in vivo applications. [20][21][22] With respect to MRI technique, [23][24][25] it is noninvasive and nondestructive, and can offer high spatial resolution, whereas it shows low sensitivity.…”