Gold Nanoparticle DNA Probes for Rapid Nucleic Acid Quantification
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Solution Overview
Problem
Conventional methods for microbial nucleic acid detection, such as culture, PCR, and immunoassay, are time-consuming, require complex operations, and have limited sensitivity, making it difficult to frequently analyze water quality, especially in developing countries and disaster areas, and they lack a sufficient measurement range for nucleic acid concentration.
Innovation Solution
A method using gold nanoparticle probes modified with DNA that binds specifically to target nucleic acids, combined with sodium chloride and optionally bovine serum albumin, to measure absorption spectra and estimate nucleic acid concentration through curve fitting, allowing for quick, accurate, and wide-range detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods (culture, PCR, immunoassay) are used for microbial nucleic acid detection, then detection sensitivity and reliability are improved, but the analysis time and operational complexity increase significantly
Solution Approach 1:
The invention extracts and utilizes the intrinsic optical properties of nucleic acids (absorption at 260nm) for direct detection, eliminating the need for time-consuming amplification steps in PCR or complex immunoassay procedures. By taking out the essential detection function and performing it directly through UV absorption measurement, the method achieves rapid results within minutes while maintaining reliability.
Solution Approach 2:
The invention replaces complex mechanical and chemical systems (PCR thermal cycling, immunoassay incubation steps) with a simple optical measurement system. By substituting the mechanical amplification process with direct optical detection of nucleic acid absorption, the method dramatically reduces analysis time while preserving detection capability.
2Measurement precision
If conventional methods are used for microbial nucleic acid detection, then detection precision is improved, but the ease of operation and accessibility deteriorate
Solution Approach 1:
The invention enables the sample to serve itself by utilizing the inherent optical absorption properties of nucleic acids. The nucleic acid extract directly absorbs UV light at 260nm, and this intrinsic property is measured without requiring external amplification reagents or complex processing. This self-service approach maintains measurement precision while dramatically simplifying operations for users in resource-limited settings.
3Measurement precision
If conventional detection methods are used, then detection sensitivity is improved, but the measurement range and dynamic range are limited
Solution Approach 1:
The invention changes the detection parameter from requiring amplification (PCR) or antibody binding (immunoassay) to direct optical absorption measurement. By measuring the absorption coefficient at 260nm, the method can detect a wide range of nucleic acid concentrations in a single measurement, providing both high sensitivity for low concentrations and the ability to measure higher concentrations without saturation, thus expanding the dynamic range.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables easy, rapid, and precise measurement of nucleic acid concentration with a broad dynamic range, facilitating efficient water quality monitoring without the need for amplification steps.
Implementation Method 1
a probe solution, being a gold nanoparticle probe solution in which DNA that binds specifically to a target nucleic acid is modified with gold nanoparticles
Implementation Method 2
acquiring an absorption spectrum of the probe solution; acquiring an absorption spectrum of a blank solution, being a sample-free solution obtained by adding sodium chloride to the probe solution and applying heat thereto; acquiring an absorption spectrum of the sample mixture
Data Source
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AI summary
A microbial nucleic acid detection method, and the like, are provided that can measure the concentration of a target nucleic acid easily, quickly, and with high accuracy, and secure a sufficient measurement range (dynamic range). The microbial nucleic acid detection method comprises the steps of: preparing a sample mixture by: mixing a probe solution, being a gold nanoparticle probe solution in which DNA that binds specifically to a target nucleic acid is modified with gold nanoparticles, with an extract obtained by applying a nucleic acid extraction treatment to a sample; and adding at least sodium chloride and applying heat thereto; acquiring an absorption spectrum of the probe solution; acquiring an absorption spectrum of a blank solution, being a sample-free solution obtained by adding sodium chloride to the probe solution and applying heat thereto; acquiring an absorption spectrum of the sample mixture; and performing calculations to estimate the concentration of the target nucleic acid in the sample based on the absorption spectra of the probe solution, the blank solution, and the sample mixture.