Hydrogen Peroxide Involved Anodic Charge Transfer and Electrochemiluminescence of All-Inorganic Halide Perovskite CsPbBr3 Nanocrystals in an Aqueous Medium

Perovskite-based electrochemiluminescence analysis of H2O2

The detection of hydrogen peroxide (H2O2) represents an extensive requirement across various domains, including food, environmental, and medical fields. This study introduces a highly sensitive technique for the quantification of H2O2, integrating the electrochemiluminescence properties of perovskite with bio-catalyzed precipitation. A water-soluble perovskite-based electrochemiluminescence (ECL) biosensing interface was constructed, wherein H2O2 catalyzes a precipitation reaction that leads to the formation of an insoluble precipitate on the electrode surface. This occurrence effectively quenches the electrochemiluminescence signal of the perovskite, thus facilitating the quantitative detection of H2O2. The modified perovskite demonstrated excellent ECL performance, offering a stable signal source, while the bio-catalyzed precipitation reaction significantly amplified the quenching effect, thereby enhancing detection sensitivity. This strategy exhibits excellent stability and sensitivity, presenting a promising method for the detection of hydrogen peroxide, which holds great potential for applications in various fields.

Hydrogen-Bonded Organic Cocrystal-Encapsulated Perovskite Nanocrystals as Coreactant-Free Electrochemiluminescent Luminophore for the Detection of Uranium

Lead halide perovskite nanocrystals with excellent photophysical properties are promising electrochemiluminescence (ECL) candidates, but their poor stability greatly restricts ECL applications. Herein, hydrogen-bonded cocrystal-encapsulated CsPbBr3 perovskite nanocrystals (PeNCs@NHS-M) were synthesized by using PeNCs as nuclei for inducing the crystallization of melamine (M) and N-hydroxysuccinimide (NHS). The as-synthesized composite exhibits multiplicative ECL efficiencies (up to 24-fold that of PeNCs) without exogenous coreactants and with excellent stability in the aqueous phase. The enhanced stability can be attributed to the well-designed heterostructure of the PeNCs@NHS-M composite, which benefits from both moiety passivation and protection of the peripheral cocrystal matrix. Moreover, the heterostructure with covalent linkage facilitates charge transfer between PeNCs and NHS-M cocrystals, realizing effective ECL emission. Meanwhile, the NHS and M components act as coreactants for PeNCs, shortening the electron-transport distance and resulting in a significant increase in the ECL signal. Furthermore, by taking advantage of the specific binding effect between NHS-M and uranyl (UO22+), an ECL system with both a low detection limit (1 nM) and high selectivity for monitoring UO22+ in mining wastewater is established. The presence of UO22+ disrupted the charge-transfer effect within PeNCs@NHS-M, weakening the ECL signals. This work provides an efficient design strategy for obtaining stable and efficient ECLs from perovskite nanocrystals, offering a new perspective for the discovery and application of perovskite-based ECL systems.

A halide perovskite/lead sulfide heterostructure with enhanced photoelectrochemical performance for the sensing of alkaline phosphatase (ALP)

For the construction of halide perovskite-based photoelectrochemical (PEC) biosensors in aqueous solution, the balance between retaining the excellent photoelectric performances of the halide perovskite and the protective modification of the halide perovskite has always been a challenging problem. In this work, a simple and sensitive photoelectrochemical biosensor based on inorganic halide perovskite CsPbBr₃ as the photoactive material for the detection of alkaline phosphatase (ALP) was reported. The substrate sodium thiophosphate (Na₃SPO₃) can be catalyzed by ALP to produce hydrogen sulfide (H₂S), which can react with the lead site on the surface of the CsPbBr₃ film to form lead sulfide (PbS), resulting in a stable heterostructure and enhanced photocurrent intensity. The possible mechanism of enhanced photocurrent response of CsPbBr₃/PbS heterojunctions was studied in detail. This work paves a new way for applying halide perovskites in different biosensor designs.

Perovskite quantum dots as a chemiluminescence platform for highly sensitive assay of cefazolin

This paper reports on a chemiluminescence (CL) probe consist of CsPbBr₃ quantum dots (QDs) in organic phase together with Fe(II) and K₂S₂O₈ in aqueous medium for the highly selective and sensitive determination of the antibiotic, cefazolin (CFZ). The CsPbBr₃perovskite QDs prepared by the ligand assisted reprecipitation method, exhibit a narrow fluorescence at 533 nm under 460 nm excitation with a high quantum yield (42 %). The Fe(II) - S₂O₈^2- as an ultra-weak CL system is converted to a rather strong CL sensing platform in the presence of organic-phase CsPbBr₃ QDs. It was observed that CFZ exerts an enhancement effect on the CL signal of the designed probe in the linear range of 25 - 300 nM, with a low limit of detection (9.6 nM). The introduced sensor has broad application prospects in biosensing, food detection, and other fields with recovery ranging from 94 to 106 %.

All-Inorganic Lead Free Double Perovskite Li-Battery Anode Material Hosting High Li+ Ion Concentrations

Perovskite materials, as a multifunctional material, have been widely applied in the field of electrochemistry due to its ion migration properties. Although the lead based halide perovskite has been applied in the anode of the lithium battery, it is necessary to develop new lead-free perovskite anode materials because of its the instability and environmental unfriendliness. Herein, we develop a facile grinding method to prepare ultrahigh Li⁺ concentration doping Cs₂NaBiCl₆ powders, which are used as the anode material of the lithium battery. The assembled battery possesses a stable specific capacity of about 300 mA h g^-1 with over 99% Coulombic efficiency. Owing to their particular crystal structure with high adjustability, the double perovskite materials have promising potentials in lithium storage applications.

Recent Progress in Electrochemiluminescence of Halide Perovskites

Halide perovskites are a rapidly developing class of solution-processable semiconductors which, to date, have a huge impact across several scientific communities. The remarkable photophysical attributes of halide perovskites illustrate their considerable potential in the electrochemiluminescence (ECL) realm. Over the past 4 years, great progress has been achieved in using halide perovskites as ECL emitters. In this mini-review, the basic characteristics, synthetic approaches, and ECL mechanisms for halide perovskite emitters are first introduced. To the best of our knowledge, most of the reported ECL-active halide perovskites and their disclosed unique features are detailly summarized. Stabilization and interface manipulation strategies for desirable ECL performance are further highlighted. The preliminary halide perovskites-related ECL applications are finally discussed, and prospects are also anticipated.

Electrogenerated Chemiluminescence and Spectroelectrochemistry Characteristics of Blue Photoluminescence Perovskite Quantum Dots

Lead-based perovskite MAPbX₃ (MA = CH₃NH₃, X = Cl and Br) has shown great potential benefits to advance modern optoelectronics and clean energy harvesting devices. Poor structural stability is one of the major challenges of MAPbX₃ perovskite materials to overcome to achieve desired device performance. Here, we present the electrochemical stability study of CH₃NH₃PbCl_1.08Br_1.92 quantum dots (QDs) by electrogenerated chemiluminescence (ECL) and photoluminescence (PL) spectroelectrochemistry methods. Electrochemical anodization of pristine MAPbX₃ QD film results in the disproportionate loss of methylammonium and halide ions (X = Cl and Br). ECL efficiency and stability of perovskite QDs in the presence of coreactant tripropyl amine (TPrA) can be greatly improved after being incorporated into a polystyrene (PS) matrix. Mass spectrum and X-ray photoelectron spectroscopy (XPS) measurements were used to provide chemical composition variation details of QDs, which are responsible for the ECL and PL characteristics (e.g., wavelength redshift) of perovskite QDs in an electrochemical cell.

Size-selected and surface-passivated CsPbBr3 perovskite nanocrystals for self-enhanced electrochemiluminescence in aqueous media

In this work, CsPbBr3 perovskite nanocrystals (NCs) synthesized via a ligand-assisted reprecipitation method (LCPB) were discovered to emit self-enhanced electrochemiluminescence (ECL) with the surface oleylamine as both a coreactant and a stabilizer. Solvent regulation and tri-n-octylphosphine post-treatment were manipulated for size-selected and surface-passivated LCPBs, which showed remarkable aqueous ECL performance with respect to efficiency and stability. Furthermore, thanks to the self-enhancement mode with a shorter charge transfer pathway and less energy loss, the ECL efficiency obtained for these as-synthesized LCPBs in aqueous solution without any additional coreactant was up to 57.08% using the Ru(bpy)32+-tripropylamine system as the standard. As a proof-of-concept, the products were successfully employed for the bioanalyses of hydrogen peroxide, ascorbic acid, and cancer cells based on inhibition, coreaction, and impedance detection principles, respectively. More importantly, the basic properties of LCPBs in aqueous media including surface chemistry, charge transfer process, and ECL mechanism were studied systematically. Such efforts are aimed at perfecting the fundamental research of all-inorganic perovskite NCs and opening an avenue for the design of highly crystalline and luminescent perovskites as advanced ECL emitters for applications in the ECL domain.

Anodic electrochemiluminescence from CsPbBr3 perovskite quantum dots for an alkaline phosphatase assay

Fundamental mechanisms of ECL generation in a CsPbBr₃ QDs/H₂A system.

Unveiling the interfacial electrochemiluminescence behavior of lead halide perovskite nanocrystals

In this study, a three-phase heterostructure interface including glassy carbon (conducting medium), CsPbBr₃ perovskite nanocrystals (PNCs, emitter) and acetonitrile (electrolyte) is constructed for fully investigating the interfacial electrochemiluminescence (ECL) behavior of CsPbBr₃ PNCs. We find that these interfaces serve as bridges for efficient electron-hole transfer during the ECL process. As a proof of concept, the increase of the heterostructure interface area will accordingly enhance the ECL intensity of CsPbBr₃ PNCs. About seven-fold enhancement of the ECL intensity could be achieved when the interface area has triple-fold increase, which provides a new perspective to construct more efficient ECL systems via interface engineering.

Recent Advances in Aggregation-Induced Electrochemiluminescence

The emergence of the rising alliance between aggregation-induced emission (AIE) and electrochemiluminescence (ECL) is defined as aggregation-induced electrochemiluminescence (AIECL). The booming science of AIE has proved to be not only distinguished in luminescent materials but could also inject new possibility into ECL analysis. Especially in the aqueous phase and solid state for hydrophobic materials, AIE helps ECL circumvent the dilemma between substantial emission intensity and biocompatible media. The wide range of analytes makes ECL an overwhelmingly interesting analytical technique. Therefore, AIECL has gained potential in clinical diagnostics, environmental assays, and biomarker detections. This review will focus on introduction of the novel concept of AIECL, current applied luminophores, and related applications developed in recent years.

Electrochemical-Signal-Amplification Strategy for an Electrochemiluminescence Immunoassay with g-C3N4 as Tags

Signal amplification for electrochemiluminescence (ECL) has conventionally been achieved by employing effective matrixes that can accelerate the electrochemical redox processes or carry more electrochemiluminophores. Herein, a convenient signal-amplification strategy was proposed for an ECL immunoassay with carboxylated g-C₃N₄ nanosheets (NSs) as tags and carcinoembryonic antigen (CEA) as the model target via electrochemically pretreating the substrate: a glassy-carbon electrode (GCE) modified with a polymerized 2-aminoterephthalic acid (ATA) film (GCE/ATA). Bioconjugates of g-C₃N₄ NSs and the signal CEA antibody (Ab₂) (i.e., g-C₃N₄ NS-Ab₂) were immobilized on GCE/ATA via a sandwich immunoreaction to form GCE/ATA-Ab₁-Ag-Ab₂-NSs. Electrochemical-impedance spectroscopy and potential-resolved ECL characterization proved that GCE/ATA plays an important role in the electron-transfer resistance ( R_et) of the GCE/ATA-Ab₁-Ag-Ab₂-NSs for ECL and that successively scanning GCE/ATA-Ab₁-Ag-Ab₂-NSs from 0 to -1.6 V in K₂S₂O₈- and H₂O₂-containing medium could reduce the R_et and bring out 3.3-times-enhanced ECL at the 10th scan cycle compared with that of the 1st scan cycle, which was about 10.2 times the ECL of the GCE/ATA-Ab₁-Ag-Ab₂-NSs in medium containing merely K₂S₂O₈. Inspired by this, direct and successive scanning of GCE/ATA in K₂S₂O₈- and H₂O₂-containing medium was employed during fabrication, which dramatically reduced the R_et of GCE/ATA-Ab₁-Ag-Ab₂-NSs and brought out obviously enhanced ECL responses for selectively determining CEA from 0.1 pg/mL to 1 ng/mL, with a detection limit of 3 fg/mL.

Electrochemistry and Spectroelectrochemistry of Lead Halide Perovskite Films: Materials Science Aspects and Boundary Conditions

The unique optoelectronic properties of lead halide perovskites have triggered a new wave of excitement in materials chemistry during the past five years. Electrochemistry, spectroelectrochemistry, and photoelectrochemistry could be viable tools both for analyzing the optoelectronic features of these materials and for assembling them into hybrid architectures (e.g., solar cells). At the same time, the instability of these materials limits the pool of solvents and electrolytes that can be employed in such experiments. The focus of our study is to establish a stability window for electrochemical tests for all-inorganic CsPbBr₃ and hybrid organic-inorganic MAPbI₃ perovskites. In addition, we aimed to understand the reduction and oxidation events that occur and to assess the damage done during these processes at extreme electrochemical conditions. In this vein, we demonstrated the chemical, structural, and morphological changes of the films in both reductive and oxidative environments. Taking all these results together as a whole, we propose a set of boundary conditions and protocols for how electrochemical experiments with lead halide perovskites should be carried out and interpreted. The presented results will contribute to the understanding of the electrochemical response of these materials and lead to a standardization of results in the literature so that comparisons can more easily be made.