A photoacoustic flow cell for use in conducting a photoacoustic analysis of one or more samples, wherein the photoacoustic analysis comprises irradiating the sample(s) with a laser light and detecting an acoustic wave generated by a thermoelastic expansion of one or more analytes present in the sample(s) resulting from the laser light being absorbed by the analyte(s) with an acoustic sensor, the photoacoustic flow cell comprising: (a) a chamber structure that defines a chamber , a chamber inlet , and a chamber outlet , wherein either (i) a portion of the chamber structure that defines the chamber is an acoustic wall through which the acoustic wave passes through, which is configured to be in contact with the acoustic sensor located outside of the chamber, or (ii) the chamber structure is configured to locate the acoustic sensor inside of the chamber; and (b) a test structure , at least a portion of which is supported by the chamber structure and at least a portion of which is located in the chamber , wherein the test structure comprises an interior surface that defines a test passageway that passes through, or is in fluid communication with or through, the chamber inlet and outlet , wherein the interior surface of the test structure is hydrophobic and oleophobic, and , wherein the test structure : (i) comprises a test structure material that is selected from the group consisting of fused quartz, borosilicate glass, and combinations thereof, which transmits the laser light, and has an acoustic impedance (Z) in a range of about 10 7 kg/(m 2 ·s) (10 Mrayls) to about 15 . 10 6 kg/(m 2 ·s) (15 Mrayls) at a frequency of about 10 MHz; (ii) is tubular having a cross-sectional diameter in a range of about 0.1 mm to about 5 mm and a wall thickness in a range of about 5 μm to about 50 μm; and (iii) is configured so that the acoustic wave passes through the wall of the test structure. (a) a chamber structure that defines a chamber , a chamber inlet , and a chamber outlet , wherein either (i) a portion of the chamber structure that defines the chamber is an acoustic wall through which the acoustic wave passes through, which is configured to be in contact with the acoustic sensor located outside of the chamber, or (ii) the chamber structure is configured to locate the acoustic sensor inside of the chamber; and (b) a test structure , at least a portion of which is supported by the chamber structure and at least a portion of which is located in the chamber , wherein the test structure comprises an interior surface that defines a test passageway that passes through, or is in fluid communication with or through, the chamber inlet and outlet , wherein the interior surface of the test structure is hydrophobic and oleophobic, and , wherein the test structure : (i) comprises a test structure material that is selected from the group consisting of fused quartz, borosilicate glass, and combinations thereof, which transmits the laser light, and has an acoustic impedance (Z) in a range of about 10 7 kg/(m 2 ·s) (10 Mrayls) to about 15 . 10 6 kg/(m 2 ·s) (15 Mrayls) at a frequency of about 10 MHz; (ii) is tubular having a cross-sectional diameter in a range of about 0.1 mm to about 5 mm and a wall thickness in a range of about 5 μm to about 50 μm; and (iii) is configured so that the acoustic wave passes through the wall of the test structure. <EOS>