Construction principles to modify responsive performance of fluorescent receptors: From background clearance to signal enhancement

There presents a rapid development for fluorescent sensory systems in recent years, appended with multiple functions, including organelle targeting, near-infrared emission, photothermal property and so forth. These in-depth studies extend the application area undoubtedly, but an excellent responsive behavior still needs a precise control. This Review focuses on the chemical modulation for responsive performance, which is discussed mainly in two parts, improvement of signal-noise ratio and signal amplification strategy. In addition to multifaceted literatures to illustrate the ratiometric strategy, comments on background-free platform are summarized elaborately, which propose a total clearance in background by in situ reactions. As for proposal to modify the responsive spectra, the control on chemical equilibrium, introduction of an additional “amplifier” and self-assembly-featured spectra manipulated by analytes are elucidated in detail, aiming to provide a straightforward pathway to constitute a set of well-behaved receptors integrating analytes-sensing with dye-distribution, avoiding the increasing demands for a complex probe.