The widespread use of monensin (MON) as an ionophore antibiotic in poultry production has raised significant concerns regarding residue accumulation in edible tissues, particularly given its potent cardiotoxic effects and narrow safety margins in Humans. Current analytical methods for MON detection primarily rely on expensive instrumentation, limiting accessibility for routine monitoring in resource-constrained regions with expanding poultry production. This study addresses the critical need for a cost-effective, field-deployable analytical platform by developing the first Dual-emission ratiometric fluorometric sensor specifically designed for MON residue detection in poultry tissues. The innovative sensing mechanism exploits the differential fluorescence responses of Rhodamine 6G (R6G) and red-emitting carbon dots (RCDs) upon MON interaction, where selective quenching of RCD emission (608 nm) occurs simultaneously with R6G signal enhancement (550 nm) under 525 nm excitation. This Dual-response system provides unprecedented analytical robustness through built-in internal calibration, eliminating matrix interference effects that plague conventional single-wavelength methods. The sensor demonstrated exceptional performance with linear detection ranges of 0.1–8.0 ng/mL in standard solutions and 5.0–400.0 ng/g in tissue matrices, achieving recovery efficiencies of 95.9–98.0% in muscle and 96.2–96.8% in liver samples. This platform uniquely enables real-time monitoring of MON elimination kinetics, facilitating evidence-based withdrawal period determination for specific production conditions. The methodology offers developing nations and small-scale producers an accessible compliance tool without requiring sophisticated instrumentation. Future applications include multiplex ionophore detection and portable device integration for on-site screening, potentially revolutionizing antibiotic monitoring in global food supply chains.

Travoprost (TRV) is an efficient prostaglandin (PG) analogue, which is hydrolyzed by corneal esterases to its
active acid form (TRV acid) after absorption. Till now no spectrofluorimetric methods have been reported for
detection of TRV acid in biological fluids. Due to high sensitivity, simplicity and rapidity; a novel and ultrasensitive
spectrofluorometric method with an efficient solid phase extraction (SPE) technique was developed
for determination of TRV acid in aqueous humor (AH). The study relies on the fluorescence enhancement of
nitrogen-doped carbon dots (N-CDs), which were prepared via a hydrothermal treatment of triphenylamine and
citric acid. The formed nanoprobe responds with very high sensitivity to trace amounts of TRV acid through
hydrogen bonding formation, which is accompanied by an enhancement in fluorescence intensity due to N-CDs
aggregation. The proposed method showed excellent sensitivity for analyzing TRV acid in the range of 1–200 ng/
mL, with a very low limit of detection (0.29 ng/mL). Additionally, the method’s selectivity for analyzing TRV
acid in the presence of common ions and anticipated co-administered drugs was assessed. The structural and
chemical properties of the prepared N-CDs were extensively characterized using X-ray diffraction (XRD), Fourier
transform infrared (FT-IR) spectroscopy, Transmission electron microscopy (TEM), High resolution transmission

Tuberculosis (TB) remains one of the deadliest infectious diseases globally. Although the approved human Bacille-Calmette-Guérin (BCG) vaccines provide limited protection, a vaccine based on Mycobacterium tuberculosis (Mtb) has yet to be approved. Our previous findings demonstrated that s.c. immunization with heat-killed Mtb significantly increased the number of monocytic myeloid-derived suppressor cells (M-MDSC) in mice. Thus, we hypothesized that the defense against a subsequent BCG infection would be compromised in Mtb-immunized mice. Surprisingly, mice vaccinated with Mtb were protected against BCG infection and exhibited elevated frequencies and activation of dendritic cells (DC) and mycobacteria-specific T cells, despite high frequencies and suppressor activity of M-MDSC. Genetic ablation of CCR2+ monocytic cells or pharmacological intervention with all-trans retinoic acid (ATRA) reduced the frequency of Mtb-induced M-MDSC, enhanced the frequencies and activation of DC and CD4+ T cells, and resulted in decreased bacterial loads in the lungs and spleen. These findings provide new insights into TB vaccination using heat-killed Mtb despite the concurrent unwanted effects of vaccine-induced M-MDSC. M-MDSC depletion via ATRA further shifts the balance toward immunity and should be considered an adjunct host-directed therapy alongside TB vaccines in humans.