The Construction Of Multi-output Molecular Logic Circuit Based On The Combination Of Bovine Serum Albumin And Schiff Base

Molecular logic circuits are a kind of research that simulates the construction of digital circuits in the real world at the molecular scale,with the advantages of small size,fast response time,and artificial intelligence,etc.How to construct molecular logic circuits in a fast and easy way has attracted the attention of many scholars.In order to investigate whether a multi-input-dual-output molecular logic circuit can be constructed more easily based on the fluorescence resonance energy transfer mechanism in a combinatorial manner,a BSA@Schiff base complex was prepared using bovine serum albumin（BSA）with multiple hydrophobic cavities interacting with Schiff bases.Since the fluorescence emission peak of BSA has a good overlap with the fluorescence excitation peak of Schiff base,when the excitation wavelength of BSA is 280 nm（the maximum excitation wavelength of BSA）,the BSA@Schiff base complex can generate two fluorescence output signals based on fluorescence resonance energy transfer,and then use metal ions,p H or organic compounds as input signals to regulate the output signals,thus constructing a three-input-two-output molecular logic circuit.Based on this construction mechanism,BSA@Schiff base@dye molecule complexes were also prepared in this paper and used as the logic material for the construction of three-output molecular logic circuits.At the same time,it is found that van der Waals forces and hydrogen bonding usually exist between these complexes,which provides a good model for the in-depth investigation of fluorescence resonance energy transfer and electron exchange energy transfer.The main research of this paper is as follows:（1）A novel fluorescent probe was designed by combining BSA with SALOPHEN.The probe showed strong responses to Zn²⁺,Fe²⁺,Cu²⁺and EDTAH₂Na₂with its fluorescence emission peaks at 350 nm and 440 nm under 280nm excitation.Based on this,the dual output digital logic circuits with different functions are designed.In addition,the energy transfer mechanism of the probe was explored,and it was found that the fluorescent probe constructed using a combinatorial approach provided a good reference model for exploring electron exchange energy transfer.（2）A fluorescent probe complex was prepared based on the interaction of SALPHENH₂with site II on BSA.In the presence of Zn²⁺,two fluorescence emission peaks were generated at 350 nm and 426 nm based on hybridized fluorescence resonance energy transfer and electron exchange energy transfer.Based on this,a half-reducer and a dual-output molecular logic circuit were designed by using different ions as input signals to modulate it.（3）A fluorescent probe was designed using a combination of two fluorescent compounds,BSA and SAF.Under the excitation at 280 nm,this probe can produce two fluorescence emission peaks at 350 nm and 460 nm based on the fluorescence resonance energy transfer.Based on this feature,three different molecular logic circuits were constructed by modulating the two fluorescence emission peaks with different metal ions using BSA@SAF as the molecular-based logic material.（4）Based on the successful preparation of dual-output fluorescent probes using a combination approach,the dual-output molecular logic circuit and the triple-output molecular logic circuit were constructed by further forming a triple-output fluorescent probe complex by using CAL in combination with BSA@SAF and modulating its output signal with different metal ions,respectively.