The systemic characterization of aptamer cocktail for bacterial detection studied by graphene oxide-based fluorescence resonance energy transfer aptasensor

Graphene oxide-based fluorescent biosensors for pathogenic bacteria detection: A review

BACKGROUND

Pathogenic bacteria are widespread in nature and can cause infections and various complications, thereby posing a severe risk to public health. Therefore, simple, rapid, sensitive, and cost-effective methods must be developed to detect pathogenic bacteria. Biosensors are prominent platforms for detecting pathogenic bacteria owing to their high sensitivity, specificity, repeatability, and stability. With the development of nanotechnology, graphene oxide (GO) has been increasingly introduced into the construction of fluorescent biosensors to enhance their performance owing to its unique physicochemical properties.

RESULTS

This review systematically summarizes the development of GO-based fluorescent biosensors for the detection of pathogenic bacteria. First, we introduce the functionalization and modification of GO. The design and signal amplification strategies for GO-based fluorescent biosensors are also discussed. Finally, we explore the challenges and new perspectives associated with this field, with the aim of facilitating the development of GO-based fluorescent sensing technologies to prevent the spread of multidrug-resistant bacteria.

SIGNIFICANCE

This review will aid in the development of high-performance biosensors for pathogenic bacterial assays.

Aptamer-conjugated carbon-based nanomaterials for cancer and bacteria theranostics: A review

Aptamers are single-stranded oligonucleotides that link to various substrates with great affinity and selectivity, including small molecules, peptides, proteins, cells, and tissues. For this reason, they can be used as imaging agents for cancer imaging techniques. Multifunctional nanomaterials combined with imaging probes and drugs are promising cancer diagnosis and treatment candidates. On the other hand, carbon-based nanomaterials (CNMs), including such as fullerene, carbon nanotubes, carbon-based quantum dots, carbon nanohorns, graphene oxide and its derivatives carbon nanodots, and nanodiamonds, are sort of smart materials that can be used in a variety of theranostic applications, including photo-triggered therapies. The remarkable physical characteristics, functionalizable chemistry, biocompatibility, and optical properties of these nanoparticles have enabled their utilization in less-invasive therapies. The theranostic agents that emerged by combining aptamers with CNMs have opened a novel alternative for personified medicine of cancer, target-specific imaging, and label-free diagnosis of a broad range of cancers, as well as pathogens. Aptamer-functionalized CNMs have been used as nanovesicles for targeted delivery of anti-cancer agents (i.e., doxorubicin and 5-fluorouracil) to tumor sites. Furthermore, these CNMs conjugated with aptamers have shown great advantages over standard CNMs to sensitively detect Mycobacterium tuberculosis, Escherichia coli, staphylococcus aureus, Vibrio parahaemolyticus, Salmonella typhimurium, Pseudomonas aeruginosa, and Citrobacter freundii. Regrettably, CNMs can form compounds defined as NOAA (nano-objects, and their aggregates and agglomerates larger than 100 nm), that accumulate in the body and cause toxic effects. Surface modification and pretreatment with albumin avoid agglomeration and increase the dispersibility of CNMs, so it is needed to guarantee the desirable interactions between functionalized CNMs and blood plasma proteins. This preliminary review aimed to comprehensively discuss the features and uses of aptamer-conjugated CNMs to manage cancer and bacterial infections.