Proteomic profiling reveals mitochondrial toxicity of nanosilver and silver nitrate in the gill of common carp

Complementary imaging of nanoclusters interacting with mitochondria via stimulated emission depletion and scanning transmission electron microscopy

The emerging stress caused by nanomaterials in the environment is of great concern because they can have toxic effects on organisms. However, thorough study of the interactions between cells and diverse nanoparticles (NPs) using a unified approach is challenging. Here, we present a novel approach combining stimulated emission depletion (STED) microscopy and scanning transmission electron microscopy (STEM) for quantitative assessment, real-time tracking, and in situ imaging of the intracellular behavior of gold-silver nanoclusters (AuAgNCs), based on their fluorescence and electron properties. The results revealed an aggregated state of AuAgNCs within the mitochondria and an increase in sulfur content in AuAgNCs, presumably owing to their reaction with thiol-containing molecules inside the mitochondria. Moreover, AuAgNCs (100 μg/mL) induced a 75% decline in mitochondrial membrane potential and a 12-fold increase of mitochondrial reactive oxygen species in comparison to control. This mitochondrial damage may be triggered by the reaction of AuAgNCs with thiol, which provides direct imaging evidence for uncovering the action mechanism of AuAgNCs on the mitochondria. The proposed dual-imaging strategy using STED and STEM is a potential tool to offer valuable insights into cytotoxicity between subcellular structures and diverse NPs, and can serve as a key strategy for nanomaterial biosafety assessment.

Dual-key-and-lock AIE probe for thiosulfate and Ag+ detection in mitochondria

Ag⁺ ion detection has attracted much attention due to its important role in chemical and biological processes, as well as its potential threat to the environment and human health. Herein, we firstly constructed a dual-key-and-lock sensing strategy for Ag⁺ detection based on three-component co-assembly. An aggregation-induced emission luminogen (AIEgen), namely triphenylamine-thiophene-pyridinium (abbreviated to TPA-T-Py), showed unique co-assembly capability with Ag⁺ and S₂O₃^2- in PBS buffer (pH 7.4, 0.01 M). Cell imaging further proved that mitochondria can be lit up by TPA-T-Py under the dual key stimulation, which was successfully used for Ag⁺ and S₂O₃^2- detection in vitro. In brief, we provide a promising strategy for the construction of dual-lock imaging agents with organelle-targeting ability.