The oxygen states (O-states) of carbon quantum dots (CDs) play an important role, with regard to their optical properties and analytical applications. However, the rapid screening of O-states in CDs is still a great challenge, because of the complicated surface composition. In this study, it is found that the chemiluminescence (CL) intensity of prepared CDs in the presence of peroxynitrite (ONOO) is proportional to the content of C-O group-related O-states. The related mechanism discloses that the O-state-dependent CL is due to the fact that abundant C-O functional groups in CDs with high O-states could facilitate the electron transfer of the produced smaller energy gaps for strong CL emission. Hence, ONOO-induced CL can be utilized as a facile probe for the rapid screening of O-states in CDs with some advantages, such as rapid response, low cost, and easy operation. Its practicability is verified by detecting the CL of phosphorus-doped CDs with variable phosphorus-doping contents. The content of C-O group-related O-states in sulfur-/phosphorus-doped CDs measured by the proposed CL probe is consistent with X-ray photoelectron spectroscopy (XPS) characterization. This strategy can also be extended to distinguish O-states in different types of nanoparticles by tuning the CL probe molecules.

Recent advances in the detection of HClO/ClO⁻in vitro and in vivo using fluorescent, phosphorescent and chemiluminescent probes are reviewed.

The surface states of carbon nanodots (CDs) were engineered by controlling the chemical structure on the surface of the CDs, which play an important role in the chemiluminescence sensing properties of CDs towards peroxynitrite. Their application in monitoring exogenous and endogenous release of peroxynitrite in living cells is demonstrated.

The rapid and effective recognition techniques for crystal facets in noble metal nanocrystals (NCs) are highly desirable in evaluation of their catalytic performances. Herein, it was found that the variation trend of cataluminescence (CTL) intensity in the presence of propanol was proportional to the crystal facets index change of LDH-supported Pd@Au NCs. The mechanism investigation for the propanol-triggered CTL on the surface of layered double hydroxide (LDH)-supported Pd@Au NCs revealed that the abundant negative charge in the high-index facets of LDH-supported Pd@Au NCs facilitated electron transfer between NCs and volatile propanol, resulting in acceleration of the CTL reactions. Accordingly, the propanol-triggered CTL can be as an indicator for rapid screening of crystal facets in NCs. Its universality had further been verified by screening crystal facets in LDH-supported Pd NCs. The crystal facets detected by propanol CTL probe were well-matched with those obtained by conventional high-resolution transmission electron microscope. The proposed CTL strategy exhibits some advantages, such as convenient operation, rapid response, long-term stability, and low cost. And it is expected crystal facets of other kinds of NCs could be screened by replaceable CTL probe.

Electrochemical biosensors have attracted much attention in mycotoxin bioanalysis. In this review, three electrochemical biosensor technologies for mycotoxins were reviewed, including general electrochemistry, photoelectrochemistry, and electrochemiluminescence. Based on the classification of multiple electrochemical detection methods, the design schemes, recognition mechanism and probe materials were described in detail. Moreover, the characteristics and limitations of these electrochemical biosensors were summarized. The challenges and future trends of electrochemical biosensor development in mycotoxin bioanalysis were also briefly discussed in the end. This review is expected to provide some inspirations for point-of-care testing in electrochemical sensors for mycotoxins and further electrochemical analysis application.