Mechanism of Interaction of Water above the Methylammonium Lead Iodide Perovskite Nanocluster: Size Effect and Water-Induced Defective States

Water is often viewed as detrimental to organic halide perovskite stability. However, evidence highlights its efficacy as a solvent during organic perovskite liquid synthesis. This paradox prompts an investigation into water’s influence on perovskite nanoclusters. Employing first principle calculations and ab initio molecular dynamics simulations, surprisingly, we discover some subsurface layers of methylammonium lead iodide (MAPbI3) nanoclusters exhibit stronger relaxation than surface layers. Moreover, a strong quantum confinement effect enhances the band gap of MAPbI3 as the nanocluster size decreases. Notably, the water molecules above MAPbI3 nanoclusters induce rich localized defect states, generating low-lying shallow states above the valence band for the small amounts of surface water molecules and band-like deep states across the whole gap for large nanoclusters. This work provides insights into water’s role in the electronic structure and structural evolution of perovskite nanoclusters, aiding the design of water-resistant layers to protect perovskite quantum dots from ambient humidity

Accession numbers of the species used for the phylogenetic tree construction.

<p>Species newly sequenced in the present study are marked in bold. Species sequenced by the authors' group are maked by sterisks (*).</p

Distribution of top-hit species.

<p>Distribution of top-hit species.</p

DataSheet1_Dual-mode electrochemiluminescence and electrochemical sensor for alpha-fetoprotein detection in human serum based on vertically ordered mesoporous silica films.docx

In this study, we demonstrated the highly sensitive detection of alpha-fetoprotein (AFP) by electrochemiluminescence (ECL) and electrochemistry (EC) based on the gated transport of the bifunctional probe (tris(1,10-phenanthroline) ruthenium (II) chloride, Ru (phen)3Cl2) into the nanochannels of vertically ordered mesoporous silica films (VMSFs). Due to the negatively charged surface and ultrasmall pore size, VMSF displays a signal amplification effect on Ru (phen)3Cl2 and is suitable for the construction of sensors with excellent sensitivity. With the linkage of (3-glycidyloxypropyl) trimethoxysilane, the anti-AFP antibody could covalently bind to the external surface of VMSF, generating a highly specific recognized sensing interface toward AFP. When AFP is presented, the formed immunocomplex hinders the diffusion of Ru (phen)3Cl2 to the underlying electrode surface, resulting in a decreased ECL or EC response. The dual-mode detection of AFP is achieved with a relatively low limit of detection (0.56 fg/ml for ECL and 4.5 pg/ml for EC) and a wide linear range (10 fg/ml∼1 μg/ml for ECL and 10 pg/ml∼1 μg/ml for EC). Moreover, owing to the inherent anti-fouling property of VMSF, satisfactory results in the analysis of human serum were obtained, showing the great potential of the designed strategy in clinical diagnosis.</p

Approximately Unbiased (AU) test results.

<p><i>p</i><0.05 refute monophyly; <i>p</i>>0.05 do not refute the possibility of monophyly.</p><p>Results in which <i>p</i><0.05 are marked in bold and shaded in grey.</p

Gene ontology (GO) annotations of the annotated unigenes.

<p>12,503 unigenes were assigned to three GO categories containing 52 functional subcategories.</p

Venn diagram showing the comparison among <i>P. olivaceus</i> transcriptomic sequences with the known sequences from <i>D. rerio</i> and <i>P. olivaceus</i> EST deposited in the NCBI database.

<p>Venn diagram showing the comparison among <i>P. olivaceus</i> transcriptomic sequences with the known sequences from <i>D. rerio</i> and <i>P. olivaceus</i> EST deposited in the NCBI database.</p

Cluster of Orthologous Groups (COG) annotations of annotated unigenes.

<p>19,547 unigenes were classified into 26 COG categories.</p

Length distribution of the assembled (blue) and the annotated unigenes (red) of <i>P. olivaceus</i>.

<p>Length distribution of the assembled (blue) and the annotated unigenes (red) of <i>P. olivaceus</i>.</p

Summary statistics of <i>P. olivaceus</i> transcriptome sequencing and assembly.

<p>Summary statistics of <i>P. olivaceus</i> transcriptome sequencing and assembly.</p