Highly Sensitive Chemiluminescent Immunoassay of Mycotoxins Using ZIF-8-Derived Yolk-Shell Co Single-Atom Site Catalysts as Superior Fenton-like Probes

Abstract

Superior to traditional nanoscale catalysts, single-atom site catalysts (SASCs) show such merits as maximal catalysis efficiency and outstanding catalytic activity for the construction of analytical methodological platforms. Hereby, an in situ etching strategy was designed to prepare yolk-shell Co SASCs derived from ZIF-8@SiO2 nanoparticles. On the basis of direct chemical interactions between precursors and supports, the Co element with isolated atomic dispersion was anchored on ZIF-8@SiO2 nanoparticles. The Co SASCs possess high Fenton-like activity and thus can catalyze the decomposition of H2O2 to produce massive superoxide radical anions instead of singlet oxygen and hydroxyl radicals. With the activity for producing superoxide radical anion, Co SASCs can greatly improve the chemiluminescent (CL) response of a luminol system by 3133.7 times. Furthermore, the SASCs with active sites of Co–O5 moieties were utilized as the CL probes for establishment of an immunoassay method for sensitive detection of mycotoxins by adopting aflatoxin B1 as a mode analyte. The quantitation range is 10–1000 pg/mL, and the limit of detection is 0.44 pg/mL (3σ) for aflatoxin B1. The proof-of-principle work elucidates the practicability of direct chemical interactions between precursors and supports for forming SASCs with ultrahigh CL response, which can be extended to the exploitation of more sorts of SASCs for tracing biological binding events.

Brain Glucose Activated MRI Contrast Agent for Early Diagnosis of Alzheimer’s Disease

“…It can be seen from Figure S1 that ZIF-8 can be stably dispersed in water for at least 7 days. A “surface attachment” approach was utilized to obtain a ZIF-8/GOx nanocomposite. − The advantage of this approach was its preservation of the enzymatic structure and activity. After loading with GOx, ZIF-8/GOx showed a yellow color, and loading rates of about 12 wt % can be calculated using the Coomassie brilliant blue method (Figure S2).…”

“…First, ZIF-8 was synthesized through a conventional method. − 2-Methylimidazole was dissolved in 20 mL of Milli-Q water and stirred at 35 °C to form a homogeneous solution. Then, 2.25 mL of a Zn­(NO 3 ) 2 ·6H 2 O aqueous solution was rapidly added.…”

Synergetic Dual-Site Atomic Catalysts for Sensitive Chemiluminescent Immunochromatographic Test Strips

“…In detail, various chlorides of Fe 2+ , Fe 3+ , Cu 2+ , Co 2+ , Mn 2+ , Ni 2+ , and Cr 3+ were adopted to boost the CL responses . As seen in Figure S1A, CoCl 2 possesses the maximal catalytic properties (∼214.6 times) among these metal ions because of highly Fenton-like activity . To furtherly testify the role of the element type, various PBAs and Co 3 N@Co SACs were synthesized through a feasible doping approach.…”

“…12 As seen in Figure S1A, CoCl 2 possesses the maximal catalytic properties (∼214.6 times) among these metal ions because of highly Fenton-like activity. 40 To furtherly testify the role of the element type, various PBAs and Co 3 N@Co SACs were synthesized through a feasible doping approach. Preferable to the low enhancement effect of CrFe (∼1.5 times), CuFe (∼7.4 times), NiFe (∼69.0 times), and MnFe (∼1.6 times) PBAs, the enticing enhancing factor (∼2155.0 times) endowed Co 3 N@Co SACs with great promise as an ideal synergetic atomic catalyst (Figure S1B).…”

MOF-Based Mycotoxin Nanosensors for Food Quality and Safety Assessment through Electrochemical and Optical Methods

“…As a consequence of this, Fuxiang Wang et al (2022) [ 96 ] developed a switching-on fluorescent sensor platform on an ultralow intensity-based Al-MOF for the sensing of AFB1 in various tea samples, including Biluochun tea, Junshan silver needle tea, and Pu’er tea with 0.05–9.61 μM linearity concentration-response range and a 0.01167 mg/L low detection limit ( Figure 9 ). In another study, Ouyang et al (2022) [ 97 ] prepared Co SASCs on ZIF-8@SiO 2 nanoparticles using a unique in situ etching technique without requiring high temperature. The porous microreactors of Co single-atom site catalysts can accelerate H 2 O 2 decomposition and create large amounts of superoxide radical anions, increasing the chemiluminescent response of the luminol system.…”