Analytical devices that combine sensitive biological component with a physicochemical detector hold a great potential for various applications, e.g., environmental monitoring, food analysis or medical diagnostics. Continuous efforts to develop inexpensive sensitive biodevices for detecting target substances typically focus on the design of biorecognition elements and their physical implementation, while the methods for processing signals generated by such devices have received far less attention. Here, we present fundamental considerations related to signal processing in biosensor design and investigate how undemanding signal treatment facilitates calibration and operation of enzyme-based biodevices. Our signal treatment approach was thoroughly validated with two model systems: (i) a biodevice for detecting chemical warfare agents and environmental pollutants based on the activity of haloalkane dehalogenase, with the sensitive range for bis(2-chloroethyl) ether of 0.01-0.8 mM and (ii) a biodevice for detecting hazardous pesticides based on the activity of γ-hexachlorocyclohexane dehydrochlorinase with the sensitive range for γ-hexachlorocyclohexane of 0.01-0.3 mM. We demonstrate that the advanced signal processing based on curve fitting enables precise quantification of parameters important for sensitive operation of enzyme-based biodevices, including: (i) automated exclusion of signal regions with substantial noise, (ii) derivation of calibration curves with significantly reduced error, (iii) shortening of the detection time, and (iv) reliable extrapolation of the signal to the initial conditions. The presented simple signal curve fitting supports rational design of optimal system setup by explicit and flexible quantification of its properties and will find a broad use in the development of sensitive and robust biodevices.

• MeSH
• Biosensing Techniques methods   MeSH
• Chemical Warfare Agents analysis   MeSH
• Hydrocarbons, Chlorinated analysis   MeSH
• Enzymes metabolism   MeSH
• Ether analogs & derivatives   analysis   MeSH
• Hexanes analysis   MeSH
• Hydrolases metabolism   MeSH
• Calibration MeSH
• Environmental Pollutants analysis   MeSH
• Lyases metabolism   MeSH
• Signal Processing, Computer-Assisted * MeSH
• Sensitivity and Specificity MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• 1-chlorohexane MeSH Browser
• bis(2-chloroethyl)ether MeSH Browser
• Chemical Warfare Agents MeSH
• Hydrocarbons, Chlorinated MeSH
• dehydrochlorinases MeSH Browser
• Enzymes MeSH
• Ether MeSH
• haloalkane dehalogenase MeSH Browser
• Hexanes MeSH
• Hydrolases MeSH
• Environmental Pollutants MeSH
• Lyases MeSH

A nucleoside bearing a solvatochromic push-pull fluorene fluorophore (dCFL ) was designed and synthesized by the Sonogashira coupling of alkyne-linked fluorene 8 with 5-iodo-2'-deoxycytidine. The fluorene building block 8 and labeled nucleoside dCFL exerted bright fluorescence with significant solvatochromic effect providing emission maxima ranging from 421 to 544 nm and high quantum yields even in highly polar solvents, including water. The solvatochromism of 8 was studied by DFT and ADC(2) calculations to show that, depending on the polarity of the solvent, emission either from the planar or the twisted conformation of the excited state can occur. The nucleoside was converted to its triphosphate variant dCFLTP which was found to be a good substrate for DNA polymerases suitable for the enzymatic synthesis of oligonucleotide or DNA probes by primer extension or PCR. The fluorene-linked DNA can be used as fluorescent probes for DNA-protein (p53) or DNA-lipid interactions, exerting significant color changes visible even to the naked eye. They also appear to be suitable for time-dependent fluorescence shift studies on DNA, yielding information on DNA hydration and dynamics.

• Publication type
• Journal Article MeSH