  We present narrow-band photometric measurements of the exoplanet GJ 1214b
using the 10.4 m Gran Telescopio Canarias (GTC) and the OSIRIS instrument.
Using tuneable filters we observed a total of five transits, three of which
were observed at two wavelengths nearly simultaneously, producing a total of
eight individual light curves, six of these probed the possible existence of a
methane absorption feature in the 8770 - 8850 {\AA} region at high resolution.
We detect no increase in the planet-to-star radius ratio across the methane
feature with a change in radius ratio of $\Delta$R = -0.0007 $\pm$ 0.0017
corresponding to a scale height (H) change of -0.5 $\pm$ 1.2 H across the
methane feature, assuming a hydrogen dominated atmosphere. We find a variety of
water and cloudy atmospheric models fit the data well, but find that cloud-free
models provide poor fits. These observations support a flat transmission
spectrum resulting from the presence of a high-altitude haze or a water-rich
atmosphere, in agreement with previous studies. In this study the observations
are predominantly limited by the photometric quality and the limited number of
data points (resulting from a long observing cadence), which make the
determination of the systematic noise challenging. With tuneable filters
capable of high resolution measurements (R ~ 600 - 750) of narrow absorption
features, the interpretation of our results are also limited by the absence of
high resolution methane models below 1 $\mu$m.
