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A self-priming mediated chain extension cysteine catalytic oxidation-based colorimetric method for sensitive
Jiaxiang Xie1, Lixia Xia1, Juan Huang1
1Cardiovascular Surgery Department, The First Affiliated Hospital with Nanjing Medical University, Nanjing City, Jiangsu Province, 210029, China.
Insights
A new colorimetric method detects Pseudomonas aeruginosa infections using rolling circle amplification and DNAzyme catalysis. This portable approach offers sensitive, selective, and early diagnosis for critical patient care.
Area of Science:
- Biomedical Diagnostics
- Molecular Biology
- Analytical Chemistry
Background:
- Hospital-acquired infections with Pseudomonas aeruginosa (P. aeruginosa) are a significant threat, particularly to immunocompromised surgical patients.
- Early and accurate diagnosis of P. aeruginosa is crucial for effective treatment and patient outcomes.
- Existing diagnostic methods may lack portability or sensitivity for rapid point-of-care detection.
Purpose of the Study:
- To develop a novel, portable colorimetric method for the sensitive and reliable detection of P. aeruginosa.
- To establish an early diagnostic tool for P. aeruginosa infections in clinical settings.
- To leverage rolling circle amplification and DNAzyme catalysis for bacterial analysis.
Main Methods:
- A colorimetric assay was designed using rolling circle amplification (RCA) to create a detection scaffold.
- Self-priming mediated signal recycling was employed, where RCA products initiate a colorimetric reaction.
- Gold nanoparticles and G-quadruplex DNAzyme were utilized to catalyze cysteine oxidation, producing visible color changes.
Main Results:
- The developed method demonstrated a broad detection range and a low limit of detection (3.6 cfu mL⁻¹).
- The colorimetric approach exhibited good selectivity for P. aeruginosa against other bacteria.
- The assay allows for direct visual observation of results, indicating successful bacterial detection.
Conclusions:
- This novel colorimetric method provides a sensitive, selective, and portable means for P. aeruginosa detection.
- The technology holds significant potential for early diagnosis of P. aeruginosa infections in biomedical diagnostics and bio-sensing.
- The assay's simplicity and visual output facilitate rapid identification of pathogenic bacteria.
Abstract:
Nursing hospital infections with Pseudomonas aeruginosa (P. aeruginosa) pose a significant risk to human health, especially to those immunosuppressed patients receiving surgical therapy. Consequently, it is imperative to create a novel and portable P. aeruginosa analysis method for the early diagnosis of P. aeruginosa infections. For sensitive and reliable P. aeruginosa analysis, we depict here a novel colorimetric approach based on rolling circle amplification (RCA) based construction of a detection scaffold and self-priming mediated signal recycling. In this method, the RCA product is attached to a plate surface to recognize P. aeruginosa targets and initiate the chain extension mediated cysteine catalytic oxidation based colorimetric reaction. This method involves activating RCA to generate several RCA products with repetitive functional portions by cyclizing the padlock sequence using primer sequences. To facilitate the color reaction based on gold nanoparticles, the produced G-rich sequences during the self-priming mediated signal recycling process can fold to G-quadruplex DNAzyme, which can catalyze the conversion of cysteine to cystine and produce color changes that can be observed directly with the naked eye. Based on this elegant design, the method has a broad detection range and a low limit of detection of 3.6 cfu mL-1. In addition, this colorimetric approach showed good selectivity to target bacteria. This technology has great potential for use in biomedical diagnostics and bio-sensing of pathogenic bacteria.
