Universal Near-Infrared Fluorescent Nanoprobes for Detection and Real-Time Imaging of ATP in Real Food Samples, Living Cells, and Bacteria

Abstract

Adenosine triphosphate (ATP), an essential metabolite for active microorganisms to maintain life activities, has been widely regarded as a marker of cell activity and an indicator of microbial contamination. Herein, we designed two near-infrared (NIR) fluorescent nanoprobes named CYA@ZIF-90 and CYQ@ZIF-90 by encapsulating the NIR dye CYA/CYQ in ZIF-90 for the rapid detection of ATP. Between them, nanoprobe CYA@ZIF-90 can achieve higher NIR emission (702 nm) and rapid detection (2 min). Based on the superior spatiotemporal resolution imaging of ATP fluctuations in living cells, the applicability of CYA@ZIF-90 for imaging and detection of ATP in living bacteria was explored for the first time. The nanoprobe indirectly realizes the quantitative detection of bacteria, and the detection limit can be as low as 74 CFU mL–1. Therefore, the prepared nanoprobe is expected to become a universal ATP sensing detection tool, which can be further applied to evaluate cell apoptosis, cell proliferation, and food-harmful microbial control.

Dual pH- and ATP-Responsive Antibacterial Nanospray: On-Demand Release of Antibacterial Factors, Imaging Monitoring, and Accelerated Healing of Bacteria-Infected Wounds under NIR Activation

“…This shift was attributed to the introduction of −NH 2 moieties, which led to an increase in the 2θ diffraction angle from 6.42 to 6.83° . However, the encapsulation of the photosensitizer ICG within the ZIF-90 core did not significantly alter the crystalline shape of ZIF-90, and ZIF-90@ICG still displayed the characteristic diffraction peaks (011), (200), (112), (022), (013), and (222) of the original ZIF-90. , Ultimately, MXene/ZIF-90@ICG nanocomposites were prepared by covalent cross-linking and exhibited the characteristic (002) diffraction peak of MXene, albeit with a notably shifted and diminished peak at 4.35°, as well as six distinct diffraction peaks corresponding to ZIF-90@ICG. , The chemical compositions of the nanomaterials were comprehensively analyzed using X-ray photoelectron spectroscopy (XPS). The prepared MXene/ZIF-90@ICG nanocomposites exhibited peaks at 284.8, 398.8, 458.8, 531.8, and 1021.8 eV in Figure B, corresponding to the binding energies of C 1s, N 1s, Ti 2p, O 1s, and Zn 2p, respectively.…”

“…Based on previous studies, − the experimental procedures were further streamlined and optimized to synthesize amino-modified MXene nanosheets and ZIF-90@ICG nanoparticles, respectively, as depicted in Scheme A. Their morphological study was carried out by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).…”

“…aureus were selected as the representative bacteria of Gram-negative bacteria and Gram-positive bacteria for the evaluation of broad-spectrum antibacterial activity, respectively. ATP serves as a widely recognized marker of cellular activity and functions as an indicator of microbial contamination. , First, the effects of different nanomaterials (PBS, 120 μg mL –1 MXene-NH 2 , 20 μM ICG, 120 μg mL –1 ZIF-90@ICG, and 120 μg mL –1 MXene/ZIF-90@ICG), with or without NIR irradiation (808 nm, 1.5 W cm –2 ) in different pH environments on bacterial vitality were assessed. Meanwhile, the final test system concentration was established at 10 6 CFU mL –1 , indirectly ensuring an equivalent ATP level throughout this process.…”

“…A dual pH- and ATP-responsive nanoparticle ZIF-90@ICG was synthesized by encapsulating ICG within the nuclear pore of ZIF-90 according to the previous method with slight modification . ZIF-90@ICG nanoparticles were hyperdispersed in a methanol solution at a concentration of 2 mg mL –1 for 24 h for functional group activation in advance.…”