Currents from single ionic channels are commonly analyzed with the assumption of intrinsically stochastic behavior. However, recent evidence suggests the presence of short and long-term correlations. Previous works determined the scaling exponents of single-channel currents using the Hurst exponent, even though the existence of a linear trend could result in overestimation of the exponent. To prevent such overestimation, we analyzed single-channel currents using detrended fluctuation analysis (DFA), which is the most commonly used method to determine the fractal-scaling index. The currents were simulated using a chaotic map that can reproduce key properties of the gating of ionic channels while producing long-term correlations. The aim was to determine the origin of correlations described in previous work. The results show that scaling exponents estimated from single-channel currents could be determined by fluctuations on a long time scale with only a slight influence of pore fluctuations occurring on short time scales. In addition, the results suggest that the overestimation of the scaling exponents by Hurst analysis could arise from the underlying trends in the single-channel currents. Overall, we conclude that single-channel currents must be analyzed using the DFA method while considering the different time scales and channel states separately.