چكيده به لاتين
The development of on-site and convenient strategy for the chiral recognition of enantiomers is of considerable significance for medical and life science. Amongst, tryptophan (Trp) is an essential amino acid for humans and plays crucial roles in many metabolic functions which its concentration levels can be applied for diagnosing different kinds of metabolic disorders and the symptoms associated with those diseases. Therefore, in this thesis, a centrifugal microchip reactor with channels packed with chiral recogenation metal-organic frameworks L-AA-Cu(II)-MOF and ZIF-8-L-His-MOF and integration with a selective colorimetric sensor based on morphology control and surface protection of gold nanoovals (NOs) with L-tyrosine (L-Tyr) and D/L-alanine (D/L-Ala) on a Polydimethylsiloxane chip and Fabrian paper were developed. Microchip systems are used for microcurrents inside microchannels in very small microliter and nanoliter dimensions and have made a great contribution to the development of methods with small sample volume in analytical chemistry. FE-SEM, TEM, FTIR, CD, UV-Vis, zeta potential, DLS and XRD characterization methods showed that chiral detection elements were successfully synthesized. The color change of the sensors from red to purple and blue was obtained due to the aggrigation of particles and the change of their orientation for D-Trp and L-Trp, respectively. The operational variables of pH and response time for each of the colorimeteric sensors were calculated as well as the appropriate figures of merit such as the suitable linear range from 0.05 to 1.5 mM on each of the corresponding sensors, and the corresponding detection limit values were respectively for the Au- sensor. NOs-L-Tyr, 15 μM and for Au-NOs-D,L-Ala sensor, 22.7 μM was calculated. The proposed sensors showed good selectivity and reproducibility in the presence of other similar species. This strategy is also applied for enantio-selective sensing in bovine serum albumin (BSA), blood plasma and urine samples with desirable performances. More importantly, on-site signal recording with a smartphone was successfully combined to perform noticeable visual color change and hold great promise in practical applications.
