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Aptamer selection and aptasensor construction for bone density biomarkers
Raja Chinnappan1, Norhan Sameh Zaghloul2, Razan AlZabn1
1Department of Chemistry, Alfaisal University, Al Zahrawi Street, Al Maather, Al Takhassusi Rd, Riyadh, 11533, Saudi Arabia.
Talanta
|December 31, 2020
Summary
New aptasensors offer a sensitive and cost-effective method for detecting osteoporosis biomarkers osteocalcin (OC) and beta-crosslap (BC). These aptamer-based biosensors overcome limitations of traditional antibody assays, enabling better monitoring of bone disease and therapeutic responses.
Area of Science:
- Biomarker Discovery
- Biosensor Technology
- Biochemistry
Background:
- Osteoporosis (OP) is characterized by bone metabolism dysregulation, leading to porous bones.
- Osteocalcin (OC) and beta-crosslap (BC) are key biomarkers for bone formation and resorption, respectively.
- Current antibody-based assays for OC and BC have limitations including thermostability, sensitivity, animal use, and cost.
Purpose of the Study:
- To develop novel aptamer-based assays for sensitive and specific detection of OC and BC.
- To overcome the limitations associated with traditional antibody-based detection methods for osteoporosis biomarkers.
- To fabricate and validate graphene oxide-based aptasensors for OC and BC detection.
Main Methods:
- Systematic evolution of ligands by exponential enrichment (SELEX) was used to select specific DNA aptamers for OC and BC.
- Binding affinity (Kd) of selected aptamers was evaluated against respective biomarkers.
- Graphene oxide-based aptasensors were fabricated using high-affinity aptamers and tested with spiked buffer and rat serum samples.
Main Results:
- High-affinity aptamers for OC and BC were successfully selected with Kd values of 59 nM and 55 nM, respectively.
- Fabricated aptasensors achieved low detection limits of 0.4 pg/ml for OC and 0.21 pg/ml for BC.
- The aptasensors demonstrated effective detection and validation in serum samples from osteoporotic rats.
Conclusions:
- Aptamer-based assays, specifically graphene oxide aptasensors, provide a promising alternative for detecting osteoporosis biomarkers OC and BC.
- These novel aptasensors offer high sensitivity, specificity, and overcome drawbacks of conventional antibody-based methods.
- The developed aptasensors hold potential for improved diagnostics and monitoring of osteoporosis and related therapies.
