A theophylline quartz crystal microbalance biosensor based on recognition of RNA aptamer and amplification of signal

Abstract

A quartz crystal microbalance (QCM) biosensor for theophylline was developed by recognition of RNA aptamer and gold nanoparticle amplification technique. Firstly, a designed small single-stranded RNA, RNA1, was immobilized onto the QCM electrode through a thiol linker. Then, the complementary stranded RNA2, which can combine with RNA1 to form a double-stranded RNA with a recognition unit of theophylline, could be self-assembled on the QCM electrode surface through a hybrid reaction in the presence of theophylline. The recognition process could cause a frequency change of QCM to give the signal related to theophylline. When RNA2 was tethered to gold nanoparticles, the signal could be amplified to further enhance the sensitivity of the designed sensor. Under the optimal conditions, the QCM-based biosensor showed excellent sensitivity (limit of detection, 8.2 nM) and specificity with a dissociation constant of Kd = 5.26 × 10(-7) M. The sensor can be used to quantitatively detect theophylline in serum, suggesting that it can be applied in complex biological samples.

Selection and Biosensor Application of Aptamers for Small Molecules

“…The bronchodilator is used for asthmatic conditions and very frequently clinically monitored. Several sensors using different theophylline aptamers were used to detect it in serum (Ferapontova et al, 2008 ; Sato et al, 2012 ; Dong and Zhao, 2013 ; Jiang et al, 2015 ). The same is true for aminoglycoside antibiotics: As overdosing can lead to hearing loss, tinnitus, and kidney failure, careful monitoring of their blood concentration is necessary.…”

Analytical methods for sensing of health-hazardous arsenic from biotic and abiotic natural resources

“…254 It has become a powerful analytical approach for detecting specic analytes due to its nanogram-level sensitivity and wide range applications in both gas phase and aqueous systems. [255][256][257] Both QCM and SAW devices used in experimental setups normally acquire two measurements, that is the phase (Ph) or frequency (F) and the amplitude (A) or energy dissipation (D) of the wave. The above two factors have been found to be dependent on the mass and mechanical-viscoelastic properties of the bound material and this is the reason behind the massive information that can be derived using these systems, making acoustic wave sensors a wonderful method in analyte detection studies.…”

Biosensor Design with Molecular Engineering and Nanotechnology

“…Figure 3.8 shows the structure of the RNA aptamer that binds theophylline tightly (K d ¼ 300 nM) with a 10,000-fold less tight binding to caffeine, from which it differs by only a methyl group. This aptamer has been used in biosensors to detect theophylline [38,39]. Although aptamers to many hundreds of targets have been generated, SELEX is quite a labour intensive process and there are on-going efforts to improve throughput by using automated liquid handling systems, better selection protocols and combined techniques such as capillary electrophoresis, microfluidics and next generation sequencing [40][41][42][43].…”