Fluorescence Probes for Cancer Imaging and Diagnostics

Fluorescence probes have emerged as indispensable tools in the detection, localisation and characterisation of cancerous tissues. By converting specific molecular interactions into optical signals, these agents enable real-time visualisation of tumours with high sensitivity and spatial resolution. Modern designs favour “off–on” activatable probes that remain non-fluorescent until triggered by tumour-associated enzymes or microenvironmental cues, dramatically improving target-to-background contrast. Wavelength tuning into the near-infrared window minimises tissue autofluorescence and enhances penetration depth, supporting both endoscopic diagnostics and intraoperative guidance. Advances in molecular design—from rational quantum chemical prediction of spirocyclisation equilibria to combinatorial screening libraries—have accelerated the development of probes targeting enzymes such as γ-glutamyltranspeptidase, dipeptidylpeptidase IV and β-galactosidase. Alongside purely diagnostic applications, multifunctional probes incorporating photothermal or photodynamic effectors are enabling seamless integration of imaging and therapy. Collectively, these innovations are poised to refine margin assessment, detect micrometastases and guide personalised surgical interventions on a global scale.

Research from Nature Portfolio

Computationally guided molecular design has now permitted accurate prediction of fluorogenic probe behaviour. By modelling spirocyclisation equilibria of hydroxymethyl rhodamine scaffolds in explicit water, researchers have rationally crafted red and yellow probes optimised for activation by γ-glutamyltranspeptidase. These tailored probes exhibit predictable open–closed equilibria, high fluorescence enhancement and streamlined synthesis, representing a shift away from purely empirical screening. In parallel, the identification of β-galactosidase as a key biomarker for peritoneal metastasis in gastric cancer has led to the development of β-galactosidase-activatable probes. When applied to both animal models and freshly resected human specimens, these agents illuminate minute metastatic nodules with exceptional contrast, underscoring their promise for intraoperative detection of occult lesions.

Fluorescence Probes for Cancer Imaging and Diagnostics publication trend

The graph below shows the total number of articles in fluorescence probes for cancer imaging and diagnostics across all publications each year (not limited to Nature Index journals).

Technical terms

Activatable fluorescence probe: A sensor that is non-fluorescent until it interacts with a specific biological trigger, producing a fluorescence “turn-on” signal.

Spinnerisation (spirocyclisation): A reversible intramolecular reaction that toggles a probe between fluorescent (open) and non-fluorescent (closed) forms.

Ratiometric fluorescence imaging: A technique that measures fluorescence intensity at two wavelengths to correct for probe concentration and environmental factors, improving quantitation.

Near-infrared (NIR) fluorescence: Emission of light in the 650–900 nm range, which offers deeper tissue penetration and reduced background autofluorescence.

Photothermal therapy (PTT): A treatment modality in which absorbed light energy is converted into heat to ablate cancer cells, often guided by a fluorescent probe.

References

1. Molecular design strategy of fluorogenic probes based on quantum chemical prediction of intramolecular spirocyclization. Communications Chemistry (2020).
2. β-Galactosidase is a target enzyme for detecting peritoneal metastasis of gastric cancer. Scientific Reports (2021).
3. Most recent advances on enzyme‐activatable optical probes for bioimaging. Aggregate (2021).
4. γ-Glutamyl transpeptidase-activatable near-infrared nanoassembly for tumor fluorescence imaging-guided photothermal therapy. Theranostics (2021).
5. Development of a fluorescent probe library enabling efficient screening of tumour-imaging probes based on discovery of biomarker enzymatic activities. Chemical Science (2022).