Label-free picomolar detection of Pb2+ using atypical icosahedra gold nanoparticles and rolling circle amplification

• Published in: Biosensors & bioelectronics 2014-09, Vol.59, p.314-320
• Main Authors: Peng, Yi, Li, Lidong, Yi, Xiaohui, Guo, Lin
• Format: Article
• Language: English
• Subjects: Amplification; Atypical icosahedra gold nanoparticles (AI-AuNPs); Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensors; Biotechnology; Cations, Divalent - analysis; Density; Detection; DNA Primers - chemistry; DNA Primers - metabolism; DNA, Catalytic - metabolism; DNAzymes; Electrochemical; Electrochemical Techniques - instrumentation; Electrodes; Equipment Design; Fundamental and applied biological sciences. Psychology; Gold; Gold - chemistry; Lead - analysis; Lead ions (Pb2+); Limit of Detection; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Nanoparticles; Nucleic Acid Amplification Techniques - instrumentation; Nucleic Acid Hybridization; Rolling circle amplification (RCA); Specific surface
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2014.03.025

A novel electrochemical sensing system for Pb2+ has been developed based on atypical icosahedral gold nanoparticle (AI-AuNPs) modification and the improved rolling circle amplification (RCA). The newly synthesized AI-AuNPs which were applied to modify the gold electrode surface greatly enhanced the sensitivity and expanded the detection range due to its large specific surface area and a large density of irrational kinks and step atoms on the particle surface. Additionally, the improved RCA introduced a manipulated circular template DNA which can be hybridized with the primer obtained from the DNAzymes catalysis reaction in the presence of Pb2+ as a cofactor to simplify the RCA procedure, and the largely elongated RCA products at the same time efficiently blocked the electron transfer at the electrode surface, thus significantly increased the electrochemical signal. The design of the label free electrochemical impendence sensing strategy was evidenced to be a highly sensitive and selective method for the lead ions monitoring compared with the previous reports and the detection range was 1pM–1μΜ with a detection limit of 290fM (3δ rule). Furthermore, the proposed detection system was also environmental-friendly and inexpensive, which can be successfully used in real serum sample detection. [Display omitted] •Developed a highly sensitive method for heavy metal ions Pb2+ detection in serum.•The modified RCA method significantly increased the sensitivity.•The new material expanded enlarged the detection range dramatically.