Preparation And Property Study Of Sensors Based On Boronic Acid Affinity Interaction

The interaction of reversible covalent binding between the boronic acid group and cis-diol-containing molecules has been widely employed as main driving force in the process of molecular recognition,which endows boronic acid based sensor with varied advantages,such as high affinity,good stability,and high selectivity.Some advanced materials and technology including nanomaterials,molecular imprinting technology,and polymer science have been introduced to develop boronic acid based sensors for different target molecules assay,which display unique advantages and promising prospects.In this paper,to realize the selective and sensitive detection of target molecules,boronic acid derivatives were used as recognition elements to design and fabricate three sensors.And the recognition and detection properties of the sensors have been investigated.Contents as follows:1.A molecular imprinting polymer?MIP?based electrochemical sensor was successfully prepared for dopamine?DA?recognition and detection using pyrrole-phenylboronic acid?py-PBA?as a novel electropolymerized monomer.py-PBA could form cyclic boronic ester bond with DA,thus endowing a double recognition capacity of the sensor to DA in the combination of the imprinted effect of MIP.Compared with the sensor prepared using pyrrole or phenylboronic acid as electropolymerized monomer,the present sensor exhibited a remarkable high imprinted factor to DA.Under the optimal conditions,the sensor could recognize DA from its analogues and monosaccharides.A linear ranging from 5.0 × 10^-8 to 1.0 × 10^-5 mol/L for the detection of DA was obtained with a detection limit of 3.3 × 10^-8 mol/L?S/N=3?.The sensor has been applied to analyze DA in injection samples with satisfactory results.2.A facile electrochemical sensor for hydroquinone?HQ?and catechol?CC?determination was successfully fabricated by the modification of poly?3-aminophenylboronic acid??pAPBA?film and multi-walled carbon nanotubes?MWCNTs?on glassy carbon electrode?pAPBA/MWCNTs/GCE?.Based on the covalent binding between the boronic acid groups of pAPBA film and cis-diol-containing molecule,a novel substitution sensing strategy was proposed for highly sensitive determination of CC.With the addition of CC into HQ solution,covalent interaction between CC and APBA occurred and the HQ was displaced by CC,resulting in a decrease of HQ oxidation peak current and the increase of CC oxidation peak current.The summation of both current changes(?|I_HQ| + ?|I_CC|)were combined for CC sensitive detection in a concentration range of 4.0 × 10^-8 1.7 × 10^-5 mol/L with a limit of detection of 4.3 × 10-9 mol/L.The sensor was successfully applied to the determination of CC in spiked water samples.3.Gold nanoparticles?AuNPs?were non-covalently modified with 3-aminophenylboronic acid?APBA?and the amine terminated poly?N-isopropyl acrylamide??APNIPAM?to develop a dual-responsive and dual-functional colorimetric sensor for glucose assay.The modified APBA and APNIPAM endowed the sensor with obvious pH and temperature responses based on the aggregation of AuNPs,which enabled the qualitative,semi-quantitative detection of glucose by the naked eyes and qualitative detection of glucose by UV-vis spectroscopy.With the advantages of facile preparation,rapid detection,and high selectivity,the sensor has been applied in real sample detection with satisfactory results.