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Liver cancer, specifically hepatocellular carcinoma (HCC), is a malignant neoplasm of the digestive system, characterized by exceptionally high morbidity and mortality rates on a global scale. Early detection and diagnosis are critical measures for enhancing the prognosis of patients diagnosed with HCC. An improved prognosis is significantly reliant on the timely diagnosis of the disease and effective therapeutic monitoring. Activatable fluorescent probes are essential for detecting and imaging biomarkers related to disease diagnosis and in vivo imaging. This paper reviews the fluorescent probes developed over the past five years for the detection and imaging of HCC. This noninvasive optical imaging modality demonstrates significant promise in targeting pathological sites and is anticipated to facilitate potential clinical translation.

A simple, novel, and gram-scalable fluorescent probe material (NIT) containing a 2,2-diphenyl-1,3-dithiolane-bridged bis-1,8-naphthalimide unit with excellent air environment stability has been reported. NIT can effectively detect Hg${}^{2+}$ according to the variation in the fluorescence characteristics of NIT with and without Hg${}^{2+}$. The selectivity, concentration titration, pH applicable range, and detection limit of NIT in 2-methyl tetrahydrofuran/water have been investigated. The results show NIT possesses high selectivity, a wide pH applicable range of 3-13, and sensitivity to detect Hg${}^{2+}$. NIT also indicates the potential application in real environmental water samples for detecting Hg${}^{2+}$.

INDONESIA – Oil palm industry linked to Indonesia's forest loss

SINGAPORE – Scientists discover protein responsible for DNA compaction

SINGAPORE – Missing protein explains link between obesity and diabetes

SINGAPORE – Novel use of fluorescent probe shines new light to finding future anti-cancer drugs

SINGAPORE – Singapore scientists make breakthrough discovery in stomach cancer research using technology developed at Genome Institute of Singapore

AFRICA – New vaccine against five livestock diseases in progress

EUROPE – Combination therapy is more effective than monotherapy in removing beta-amyloid plaques from the brains of mice

UNITED STATES – Combination vaccine for ricin and anthrax achieves simultaneous protection milestone

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UNITED STATES – Smell and eye tests show potential to detect Alzheimer's early

UNITED STATES – Neurons, brain cancer cells require the same little-known protein for long-term survival

UNITED STATES – Transplanting gene into injured hearts creates biological pacemakers

As a new fluorescence sensor for S${}^{2-}$detection, TSPP-Ag${}^{+}$-based “on-off-on” switches were designed. 5,10,15,20-(4-sulphonatophenyl) porphyrin (TSPP) is used as a good fluorescent probe due to its high quantum yield, good water solubility and good biocompatibility. At room temperature, the TSPP releases the optimal fluorescence emission wavelength at 642 nm when the excitation wavelength is set to 515 nm. This indicates the “turn on” mode and the color of the solution demonstrated is pink at this time. The strong fluorescence of TSPP can be firstly quenched by Ag${}^{+}$ as it can chelate with N atoms in the TSPP cavity, which causes the fluorescence intensity to become weak and the color of the solution changes from pink to light green. At this point, the fluorescence signal for the study system is in the “turn-off” state. When S${}^{2-}$are added to the TSPP-Ag${}^{+}$ sensing system, the fluorescence signal is recovered again due to the generation of silver sulfide (Ag₂S), correspondingly, the solution color changed from light green to yellow-black. At this point, the fluorescence emission for the study system is in the “turn-on” state. Moreover, TSPP-Ag${}^{+}$ showed good selectivity and sensitivity towards S${}^{2-}$than other metal ions, and the limit of detection (LOD) is lowererd to 1.77 $\mu$M, the linear range is 0 - 29.21 $\mu$M. In addition, the concentration of S${}^{2-}$is detected in rabbit serum. Both of the recoveries and RSDs are within satisfactory range, which indicates that the promoted “on-off-on” fluorescent sensor can be applied to detect S${}^{2-}$in real samples.

A novel “on-off-on” switches fluorescence sensor based on TSPP-gallic acid (GA) for S${}^{2-}$-detecting was designed in this article. 5,10,15,20- (4-sulphonatophenyl) porphyrin (TSPP) was synthesized by a modified “one-pot” method. The synthesized TSPP was used as a fluorescence probe for the construction of a fluorescence sensing system. At room temperature, the maximum fluorescence emission wavelength could be obtained at 642 nm when the excitation wavelength was 515 nm when the fluorescence signal was in the “on” mode. The TSPP solution appeared pink in color at this moment. When GA was introduced into the TSPP solution, the fluorescence signal was turned off (fluorescence intensity was quenched) due to the protonation of TSPP, which was caused by the weak acidity of GA. The color of the TSPP solution changed from pink to green. Following that, an acid-base reaction between S${}^{2-}$and GA was initiated when S${}^{2-}$was introduced into the TSPP-GA system, leading to the liberation of TSPP and restoration of fluorescence intensity. The solution color reverted to red, indicating that the fluorescence sensing system had returned to the “on” mode. The TSPP-GA system had good selectivity and sensitivity to S${}^{2-}$, the linear range was 4.52 × 10${}^{-6}$ M $\sim$ 4.34 × 10${}^{-4}$ M, and the detection limit (LOD) was 0.87 $\mu$ M. It could be used to detect sulfur ions in actual samples with satisfactory recoveries and RSD values.

Herein, we have reported the synthesis of boron-, sulfur-, and nitrogen-co-doped carbon dots (B/S/N-CDs) by one-step hydrothermal method using D-($+$)-maltose monohydrate, boracic acid, and thiocarbamide as the precursors. The prepared B/S/N-CDs possess good water dispersibility, excellent pH stabilities, and resistance to photobleaching. Furthermore, the transmission electron microscope image indicates that the B/S/N-CDs are homogeneously spherical and show good dispersion. Noticeably, the B/S/N-CDs show bright blue photoluminescence with a quantum yield of 8.9% in aqueous solution and can be used as a potent photoluminescent probe for selective and sensitive detection of sunset yellow (SY). Compared with other food colors, SY can dramatically quench the fluorescence of B/S/N-CDs. Meanwhile, the fluorescence intensity displays a good linear response with SY concentration in the range of 0–70$\mu$M ($R^2=0.9980$) and the detection limit is as low as 4.65nM. The B/S/N-CDs can also be applied for the detection of SY in mineral water and business drink with satisfactory recovery. Our study has demonstrated that the B/S/N-CDs may have wide application values in medical detection, environmental monitoring, and related researches.

Nonhazardous and value-added utilization of biomass tar remains a great challenge in biomass gasification development. Herein, both model compounds and real biomass tar were for the first time tested as the carbon source for carbon quantum dots, where the resultants demonstrated excellent monodispersibility and strong fluorescence, quantum efficiency up to 53% and 43% were achieved. Moreover, the real tar-derived CQDs further revealed as a highly selective and sensitive probe for Fe${}^{3+}$, indicating its great potential ion sensing. It is expected that this work would open up a new strategy for biomass tar valorization.

A turn-on fluorometric probe is designed for the determination of ascorbic acid (AA) based on the inner filter effect (IFE) between CaF₂:${\text{Yb}}^{3+}$, ${\text{Er}}^{3+}$ upconversion nanoparticles (CaF₂:${\text{Yb}}^{3+}$, ${\text{Er}}^{3+}$ NPs) and the oxidized 3, $3^{\prime }$, 5, $5^{\prime }$-tetramethylbenzidine (oxTMB). The colorless TMB can be oxidized by H₂O₂/${\text{Cu}}^{2+}$ to blue oxTMB. Under 980 nm photoexcitation, CaF₂:${\text{Yb}}^{3+}$, ${\text{Er}}^{3+}$ NPs can emit red light, which can be absorbed by the blue oxTMB, leading to the fluorescence quenching at 657 nm. As AA can reduce the blue oxTMB to colorless TMB, the fluorescence at 657 nm can be recovered with the addition of AA, which can accomplish the detection towards AA. The linear detection range of AA is from 1 to 30 $\mu$M, and the limit of detection (LOD) of AA is 0.1 $\mu$M.

The blue–green fluorescent carbon quantum dots (BG-CQDs) were successfully synthesized by one-step hydrothermal method using chaff as the only precursor. It is found that the BG-CQDs showed excellent photostability and emitted strong blue–green fluorescence under the excitation wavelength of 330nm. And this fluorescence could be effectively quenched by curcumin (CM) based on the static quenching mechanism and inner filter effects with a wider linear range of 2.50–40$\mu$M and a lower detection limit of 3.53nM. Consequently, a sensitive fluorescence probe of BG-CQDs was designed to detect trace CM in blood and urine samples of healthy adults with satisfactory recoveries in the range of 92.07–111.85%. The research extended the applications of biomass waste, especially in the fields of sensor and biomedical monitoring.

We report a sandwich immunoassay strategy for specific isolation and detection of cancer cells. Prostate cancer LNCaP cells overexpressing PSMA (Prostate-specific membrane antigen) were used as the model target to evaluate the performance of immunoassay. Inorganic/polymer nanocomposites with Janus-like structure and enhanced fluorescence properties were synthesized and applied for immobilization of QDs and the antibodies. PSMA antibodies were covalently conjugated to the QDs@SiO₂/PS Janus-like composite nanoparticles to construct the fluorescent probes. Magnetic probes conjugated with polyclonal antibodies were used to capture and isolate the cancer cells. Results indicated high potential of the unique nanoprobes in specific isolation and detection of cancer cells.

Over recent years, our understanding of the pharmacological roles played by (HUMAN)NAT1 has increased considerably. In this chapter, we evaluate the evidence that (HUMAN)NAT1 has a role in breast cancers, in particular oestrogen-receptor-positive (ER+) tumours. We also examine how a new generation of NAT1-specific inhibitors are being used as chemical tools to evaluate the roles of (HUMAN)NAT1. Colorimetric and fluorescent analogues of a naphthoquinone inhibitor, identified by high-throughput screening, have proved particularly useful, due to their ability to detect the presence of low levels of (HUMAN)NAT1 within tumour cell samples. We also speculate on the possibilities for future research in this field, including an evaluation of in silico studies as an approach to the development of new classes of NAT1-specific inhibitors having improved physicochemical properties and an analysis of the evidence suggesting a possible link between (HUMAN)NAT1 expression levels and folate metabolism in cells.