Mathematical modeling of functionalized-microsphere based assays for rapid DNA detection: From sample preparation to results

作者：Louw Tobias M^*; Gomez Duarte Oscar G; Subramanian Anuradha; Viljoen Hendrik J

来源：Biochemical Engineering Journal, 2014, 88: 50-60.

DOI：10.1016/j.bej.2014.03.018

• Biomedical
• Diffusion-reaction
• Diagnostics
• Dynamic modeling
• Enzyme biocatalysis

Functionalized microspheres are frequently used in the detection of biomolecules. A fundamental understanding of the mechanisms involved in enzymatic assays is required to estimate a method's utility. The mathematical methodology is illustrated through a theoretical analysis to assess the performance of a diagnostic method based on the horseradish peroxidase catalyzed reaction to detect pathogens in clinical specimens. The first part of the analysis focuses on the collection of target DNA molecules onto a functionalized fiber in a lysis micro-reactor (LMR). Expressions are derived for hybridization rates that include convective transport. In the next step the fiber is contacted with functionalized chitosan microspheres containing horse radish peroxidase. Chitosan microspheres are conjugated to the fiber with the target DNA acting as a unique tether. The final step is the release of chitosan microspheres in a chromogenic substrate and monitoring absorption changes. The analysis provides estimates of the method sensitivity and processing time and we show that DNA with a concentration as low as 10(-4) copies per milliliter can be detected in less than 30 min. The modeling methodology presented can readily be extended to similar enzymatic, microsphere-based assays for quantitative purposes and feasibility studies.

• 出版日期2014-7-15