An affinity resin containing the peptide ligand Phe-Leu-Leu-Val-Pro-Leu (FLLVPL) has been developed for the purification of fibrinogen. The ligand was identified by screening a solid-phase combinatorial peptide library using an immunostaining technique. The specific binding of fibrinogen to the ligand has been characterized by isothermal calorimetry and adsorption isotherms and is dominated by both hydrophobic interactions and ionic interactions with the N-terminal free amino group. The effective association constant of fibrinogen was substantially higher when the peptide was immobilized on the resin than in solution; moreover, it increased with increasing peptide density, suggesting a cooperative binding effect. A low ionic strength buffer at pH 4 was used successfully to elute adsorbed fibrinogen from the column with high purity, retention of factor XIII crosslinking activity, and minimal, if any, loss of biological function. This general approach to ligand selection and characterization can be used to develop peptide ligands for the affinity purification of diverse proteins on a large scale.

Peptide libraries can be used to identify ligands that bind specifically to a desired protein. These peptides may have significant advantages as specific ligands for affinity chromatography separations. This article describes the use of one of such peptide, Try-Asn-Phe-Glu-Val-Leu, as a ligand for the purification of S-protein using affinity chromatography. General strategies for peptide immobilization are discussed and the conditions for peptide immobilization to Emphazetrade mark gel are optimized. The effects of peptide orientation and peptide densities on protein binding are studied. Results indicate that the peptide affinity is not affected by the orientation of the peptide during immobilization, but association constants can be reduced by one order of magnitude when compared with the values in solution.With increased peptide density, the protein binding capacity of the gel increases, but both the percentage of peptide utilization and apparent binding constant between immobilized peptide and S-protein decrease. S-protein is separated from a mixture with BSA via affinity chromatography using specific elution with the peptide in solution.Finally, direct purification of S-protein from an enzymatic digestion mixture of ribonuclease A is demonstrated.(c) 1995 John Wiley & Sons, Inc.

Two structural isomers of carbazole decorated with triarylamine have been designed and synthesized with a facile synthetic procedure. The impact of triarylamine substitution on the isomeric structural linkage of carbazole on the optical, thermal, electrochemical, and photovoltaic properties has been extensively studied by combining experimental and simulation methods. Car­[2,3] showed a red shift in the absorption maximum compared to that of Car­[1,3], indicating the linear conjugation along the 2,7-position of carbazole in the former. The high thermal decomposition temperature (>420 °C) of these compounds could be attributed to the rigid structure of the carbazole core. Perovskite solar cells fabricated with Car­[2,3] as the hole transporting material (HTM) displayed the highest power conversion efficiency (PCE) of 19.23%. It can be attributed to the suitable energy alignment of the highest occupied molecular orbital (HOMO) of HTM with the adjacent perovskite valence band energy level, which results in efficient hole transport. Furthermore, the molecular dynamic simulation demonstrates that the triphenylamine substitution on the 2,3,6,7 positions of Car­[2,3] results in a more planar molecular alignment on top of the perovskite surface, promoting an efficient hole extraction. Essentially, when Car­[1,3] and Car­[2,3] were applied in perovskite solar cells, they showed enhanced long-term stability by retaining >80% of their initial PCEs after 1000 h of continuous illumination.

alternative to the existing conventional energy sources. [1] Organometal-halide perovskites show exceptional panchromatic light harvesting ability, high molar extinction coefficient, high charge carrier mobilities, and long electron-hole diffusion lengths. Further, the versatility and tunable electronic properties of perovskites are beneficial for realizing higher photovoltaic performance reaching over 25%. [2][3][4][5] However, low charge extraction and poor stability of the metal-halide perovskite limit their credentials in large-scale applications.To overcome these limitations, p-type semiconducting materials, also known as hole-transporting materials (HTMs), were sandwiched between perovskite and metal electrode. HTMs play a vital role in PSCs to extract and transfer the positive charges and thus achieve high efficiency. [6][7][8][9][10] They can be classified as inorganic, [11] polymeric, [12] and small molecular organic HTMs. [13,14] Among them, small molecular HTMs are superior to other counterparts owing to their structural diversity, well-defined molecular Triarylamine-substituted bithiophene (BT-4D), terthiophene (TT-4D), and quarterthiophene (QT-4D) small molecules are synthesized and used as low-cost hole-transporting materials (HTMs) for perovskite solar cells (PSCs). The optoelectronic, electrochemical, and thermal properties of the compounds are investigated systematically. The BT-4D, TT-4D, and QT-4D compounds exhibit thermal decomposition temperature over 400 °C. The n-i-p configured perovskite solar cells (PSCs) fabricated with BT-4D as HTM show the maximum power conversion efficiency (PCE) of 19.34% owing to its better hole-extracting properties and film formation compared to TT-4D and QT-4D, which exhibit PCE of 17% and 16%, respectively. Importantly, PSCs using BT-4D demonstrate exceptional stability by retaining 98% of its initial PCE after 1186 h of continuous 1 sun illumination. The remarkable long-term stability and facile synthetic procedure of BT-4D show a great promise for efficient, stable, and low-cost HTMs for PSCs for commercial applications.

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