Aims: The use of semiconductor quantum dots (QD) nanoparticles with emission spectrum in the visible region as a marker in immunoassays provides the user with an opportunity to detect the desired agent without using advanced equipment. Accordingly, the aim of this study was to present a one-step conjugation method for antibodies with CdTe quantum dots, using activated dextran.
Materials and Methods: In this experimental study, CdTe nanoparticles were synthesized and the transmission electron microscope was used to study the morphology of the synthesized QD of CdTe and the size, concentration, and stability of the synthesized nanoparticles were evaluated. In order to stabilize the nanoparticles synthesized by BSA (Bovine Serum Albumin), they were coated and connected to antibodies with activated dextran. Immunosuppression tests were used to evaluate the conjugated antibodies.
Findings: Spot and spherical nature were completely evident in the morphology of nanoparticles. The difference in QD and dBSA-QD displacement from the agarose gel confirmed the formation of dBSA-QD and the same dilution spectrum from nanoparticles was obtained in the presence and absence of BSA. Connecting with dBSA, in addition to maintaining and improving the properties of the nanoparticle's diffusion led to the creation of diverse functional groups for the next steps of nanoparticle connection. The fluorescence emission of nanoparticles was higher in both coated with dBSA and conjugated with antibodies than free nanoparticles. By using antibodies connected to nanoparticles, the detection limit of 30ng for protein antigen was obtained as an eye.
Conclusion: In the conjugation process, in order to connect CdTe quantum dots to antibodies via dextran, by coating nanoparticles with a denatured BSA in addition to increasing the stability of nanoparticles, new functional groups are created on the surface of the nanoparticle.

​One of the main challenges in the treatment of genetic disorders, such as cancer, is of drug delivery systems and their inability to monitor and track delivered drug to the targeted site. Therefore, the design of novel with dual capabilities of nuclear drug delivery and tracking into a research priority for this field’s The aim of this study is to design based on both non-cytotoxic quantum dots and chimeric peptides, with dual tracking and delivering small genetic agents into the nucleus. The GQDs with green emission color were synthesized by Hummer’s and methods and characterized by UV-Vis, photoluminescence (PL), Raman spectroscopies, and scanning electron microscopy (SEM). conjugated with MPG-2H1 chimeric peptides through noncovalent interactions. Following conjugation step, the ζ-potential of the complex increased (From -38.6 to -11.1 in complex1, -9.6 in complex2 and -5.74 in complex3). The conjugation was confirmed by native acrylamide gel retardation assay. The of the GQDs was investigated by MTT assay and finally, was carried out. The results showed that MPG-2H1/ GQD complexes can enter cells; however, free-GQDs didn’t enter the cells significantly.

Graphene quantum dots (GQDs) have attracted increasing attention due to their unique properties such as high water solubility, photoluminescence activity, good biocompatibility, physical, chemical and electrical properties which makes them appropriate candidates for use in a variety of bio-applications, sensors and photocatalysts. The objective of this study is synthesis of GQDs and improving their surface properties via chemical modification.
Here, urea and citric acid as carbon precursor were used.  Citric acid was self-assembled into graphene framework via hydrothermal method at 160 °C for 4 h.  Then, the synthesized GQDs were carbonized and chemically activated by KOH treatment. The surface area and pore structures of GQDs were analyzed by nitrogen adsorption/desorption isotherms. The results showed that the specific surface area of carbonized-activated graphene quantum dots (CA-GQDs) have been increased from 0.06 to 1204.0 m²/g and pore structures have been enhanced significantly. The XRD pattern of GQDs confirmed the basic structure of graphite layer. The TEM images indicated the unique morphology of GQDs and the sizes of GQDs  were less than 5 nm. Thus, our applied method is an effective approach in the formation of GQDs with large BET surface area and narrow pore structures which reveals their potential applicability in biomedical field.

Carbon quantum dots are a new generation of carbon nanoparticles that have good potential for food analysis and packaging due to their unique properties such as excellent fluorescence properties, easy synthesis, good biocompatibility, large functional groups, and low toxicity. Today, carbon quantum dots have replaced semiconductor quantum dots due to their non-toxicity. The use of carbon dots in packaging materials due to their antioxidant, antimicrobial and barrier properties increases product shelf life, reduces the growth of microorganisms, improves mechanical properties, the barrier against gases, UV light blocker, and reduces food waste. This paper aims to get acquainted with carbon quantum dots and synthesis methods and study their optical properties. Then, the principles of fluorescence sensor design, including the mechanism of fluorescence quenching and recovery and their application in food samples to detect food additives, pathogens, antibiotic residues, insecticides, heavy metals, and nutrients will be examined. Finally, the use of carbon dots in improved, active, intelligent and bio-packaging will then be discussed.