Abstract: The present invention provides a gas sensor structure comprising a gas sensing chip. The back of the sensing material is a hollow structure. An insulating layer is below the sensing material. A micro heating is disposed surrounding the sensing material. The sensing material adheres to sensing electrodes. The sensing material is a complex structure including a metal oxide semiconductor and a roughened lanthanum-carbonate gas sensing layer. The thickness of the metal oxide semiconductor is between 0.2 ?m and 10 ?m; the thickness of the roughened lanthanum-carbonate gas sensing layer is between 0.1 ?m and 4 ?m; and the size of the back etching holes is smaller than 1*1 mm. By using the gas sensor structure according to the present invention, a suspended gas sensing structure can be fabricated on a silicon substrate and the chip size can be minimized.

Abstract: The present invention provides a gas sensor structure comprising a gas sensing chip. The back of the sensing material is a hollow structure. An insulating layer is below the sensing material. A micro heating is disposed surrounding the sensing material. The sensing material adheres to sensing electrodes. The sensing material is a complex structure including a metal oxide semiconductor and a roughened lanthanum-carbonate gas sensing layer. The thickness of the metal oxide semiconductor is between 0.2 ?m and 10 ?m; the thickness of the roughened lanthanum-carbonate gas sensing layer is between 0.1 ?m and 4 ?m; and the size of the back etching holes is smaller than 1*1 mm. By using the gas sensor structure according to the present invention, a suspended gas sensing structure can be fabricated on a silicon substrate and the chip size can be minimized.

Abstract: A method is provided for purifying protein having steps of loading a sample containing proteins into a column containing an ion exchanger in a first direction to allow the ion exchanger to absorb proteins; and passing a salt solution through the column in a second direction opposite to the first direction to elute a target protein from the ion exchanger. The method is proven as capable of improving homogeneity of eluted target protein without combining minute and complicated techniques for protein purification. Therefore, the method is convenient, efficient and economic for purifying proteins.

Abstract: A method is provided for purifying protein having steps of loading a sample containing proteins into a column containing an ion exchanger in a first direction to allow the ion exchanger to absorb proteins; and passing a salt solution through the column in a second direction opposite to the first direction to elute a target protein from the ion exchanger. The method is proven as capable of improving homogeneity of eluted target protein without combining minute and complicated techniques for protein purification. Therefore, the method is convenient, efficient and economic for purifying proteins.